2020
|
T D Bucio, C Lacava, M Clementi, J Faneca, I Skandalos, A Baldycheva, M Galli, K Debnath, P Petropoulos, F Gardes Silicon Nitride Photonics for the Near-Infrared Journal Article IEEE Journal of Selected Topics in Quantum Electronics, 26 (2), 2020. Abstract | Links | Tags: silicon nitride, Silicon photonics, silicon-rich @article{Bucio2020,
title = {Silicon Nitride Photonics for the Near-Infrared},
author = {T D Bucio and C Lacava and M Clementi and J Faneca and I Skandalos and A Baldycheva and M Galli and K Debnath and P Petropoulos and F Gardes},
doi = {10.1109/JSTQE.2019.2934127},
year = {2020},
date = {2020-01-01},
journal = {IEEE Journal of Selected Topics in Quantum Electronics},
volume = {26},
number = {2},
abstract = {In recent years, silicon nitride (SiN) has drawn attention for the realisation of integrated photonic devices due to its fabrication flexibility and advantageous intrinsic properties that can be tailored to fulfill the requirements of different linear and non-linear photonic applications. This paper focuses on our progress in the demonstration of enhanced functionalities in the near infrared wavelength regime with our low temperature (textless350 ^$backslash$circC) SiN platform. It discusses (de)multiplexing devices, nonlinear all optical conversion, photonic crystal structures, the integration with novel phase change materials, and introduces applications in the 2 $backslash$mum wavelength range.},
keywords = {silicon nitride, Silicon photonics, silicon-rich},
pubstate = {published},
tppubtype = {article}
}
In recent years, silicon nitride (SiN) has drawn attention for the realisation of integrated photonic devices due to its fabrication flexibility and advantageous intrinsic properties that can be tailored to fulfill the requirements of different linear and non-linear photonic applications. This paper focuses on our progress in the demonstration of enhanced functionalities in the near infrared wavelength regime with our low temperature (textless350 ^$backslash$circC) SiN platform. It discusses (de)multiplexing devices, nonlinear all optical conversion, photonic crystal structures, the integration with novel phase change materials, and introduces applications in the 2 $backslash$mum wavelength range. |
2019
|
R Marchetti, C Lacava, L E E Carroll, K Gradkowski, P Minzioni Coupling strategies for silicon photonics integrated chips [invited] Journal Article Photonics Research, 7 (2), pp. 201–239, 2019. Abstract | Links | Tags: coupling, granting coupler, Silicon photonics, surface coupler @article{Marchetti2019,
title = {Coupling strategies for silicon photonics integrated chips [invited]},
author = {R Marchetti and C Lacava and L E E Carroll and K Gradkowski and P Minzioni},
doi = {10.1364/PRJ.7.000201},
year = {2019},
date = {2019-01-01},
journal = {Photonics Research},
volume = {7},
number = {2},
pages = {201--239},
abstract = {Over the last 20 years, silicon photonics has revolutionized the field of integrated optics, providing a novel and powerful platform to build mass-producible optical circuits. One of the most attractive aspects of silicon photonics is its ability to provide extremely small optical components, whose typical dimensions are an order of magnitude smaller than those of optical fiber devices. This dimension difference makes the design of fiber-to-chip interfaces challenging and, over the years, has stimulated considerable technical and research efforts in the field. Fiber-to-silicon photonic chip interfaces can be broadly divided into two principle categories: in-plane and out-of-plane couplers. Devices falling into the first category typically offer relatively high coupling efficiency, broad coupling bandwidth (in wavelength), and low polarization dependence but require relatively complex fabrication and assembly procedures that are not directly compatible with wafer-scale testing. Conversely, out-of-plane coupling devices offer lower efficiency, narrower bandwidth, and are usually polarization dependent. However, they are often more compatible with high-volume fabrication and packaging processes and allow for on-wafer access to any part of the optical circuit. In this paper, we review the current state-of-the-art of optical couplers for photonic integrated circuits, aiming to give to the reader a comprehensive and broad view of the field, identifying advantages and disadvantages of each solution. As fiber-to-chip couplers are inherently related to packaging technologies and the co-design of optical packages has become essential, we also review the main solutions currently used to package and assemble optical fibers with silicon-photonic integrated circuits.},
keywords = {coupling, granting coupler, Silicon photonics, surface coupler},
pubstate = {published},
tppubtype = {article}
}
Over the last 20 years, silicon photonics has revolutionized the field of integrated optics, providing a novel and powerful platform to build mass-producible optical circuits. One of the most attractive aspects of silicon photonics is its ability to provide extremely small optical components, whose typical dimensions are an order of magnitude smaller than those of optical fiber devices. This dimension difference makes the design of fiber-to-chip interfaces challenging and, over the years, has stimulated considerable technical and research efforts in the field. Fiber-to-silicon photonic chip interfaces can be broadly divided into two principle categories: in-plane and out-of-plane couplers. Devices falling into the first category typically offer relatively high coupling efficiency, broad coupling bandwidth (in wavelength), and low polarization dependence but require relatively complex fabrication and assembly procedures that are not directly compatible with wafer-scale testing. Conversely, out-of-plane coupling devices offer lower efficiency, narrower bandwidth, and are usually polarization dependent. However, they are often more compatible with high-volume fabrication and packaging processes and allow for on-wafer access to any part of the optical circuit. In this paper, we review the current state-of-the-art of optical couplers for photonic integrated circuits, aiming to give to the reader a comprehensive and broad view of the field, identifying advantages and disadvantages of each solution. As fiber-to-chip couplers are inherently related to packaging technologies and the co-design of optical packages has become essential, we also review the main solutions currently used to package and assemble optical fibers with silicon-photonic integrated circuits. |
U A Korai, Z Wang, C Lacava, L R Chen, I Glesk, M J Strain Technique for the measurement of picosecond optical pulses using a non-linear fiber loop mirror and an optical power meter Journal Article Optics Express, 27 (5), pp. 6377–6388, 2019. Abstract | Links | Tags: @article{Korai2019,
title = {Technique for the measurement of picosecond optical pulses using a non-linear fiber loop mirror and an optical power meter},
author = {U A Korai and Z Wang and C Lacava and L R Chen and I Glesk and M J Strain},
doi = {10.1364/OE.27.006377},
year = {2019},
date = {2019-01-01},
journal = {Optics Express},
volume = {27},
number = {5},
pages = {6377--6388},
abstract = {A method for measuring picosecond pulse width by using only fiber components and optical power meters is presented. We have shown that the output power splitting ratio of a non-linear fiber loop mirror can be used to extract the full-width half maximum of the optical pulse, assuming a known slowly varying envelope shape and internal phase structure. Theoretical evaluation was carried out using both self-phase and cross-phase modulation approaches, with the latter showing a twofold sensitivity increase, as expected. In the experimental validation, pulses from an actively fiber mode-locked laser at the repetition rate of 10 GHz were incrementally temporally dispersed by using SMF–28 fiber, and then successfully measured over a pulse width range of 2–10 ps, with a resolution of 0.25 ps. This range can be easily extended from 0.25 to 40 ps by selecting different physical setup parameters.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
A method for measuring picosecond pulse width by using only fiber components and optical power meters is presented. We have shown that the output power splitting ratio of a non-linear fiber loop mirror can be used to extract the full-width half maximum of the optical pulse, assuming a known slowly varying envelope shape and internal phase structure. Theoretical evaluation was carried out using both self-phase and cross-phase modulation approaches, with the latter showing a twofold sensitivity increase, as expected. In the experimental validation, pulses from an actively fiber mode-locked laser at the repetition rate of 10 GHz were incrementally temporally dispersed by using SMF–28 fiber, and then successfully measured over a pulse width range of 2–10 ps, with a resolution of 0.25 ps. This range can be easily extended from 0.25 to 40 ps by selecting different physical setup parameters. |
K R H Bottrill, M A Ettabib, I Demirtzioglou, R Marchetti, C Lacava, F Parmigiani, D J Richardson, P Petropoulos Spectral Difference Interferometry for the Characterization of Optical Media Journal Article Laser and Photonics Reviews, 13 (10), 2019. Abstract | Links | Tags: @article{Bottrill2019,
title = {Spectral Difference Interferometry for the Characterization of Optical Media},
author = {K R H Bottrill and M A Ettabib and I Demirtzioglou and R Marchetti and C Lacava and F Parmigiani and D J Richardson and P Petropoulos},
doi = {10.1002/lpor.201900007},
year = {2019},
date = {2019-01-01},
journal = {Laser and Photonics Reviews},
volume = {13},
number = {10},
abstract = {A new form of interferometry combining high phase sensitivity and excellent mechanical isolation is proposed and demonstrated. These features arise from maintaining a probe and reference tone in the same medium under test at all times, their ultimate homodyne detection, as well as a novel method employing an optical programmable filter which is used to extract their relative phase difference. A compilation of studies performed to illustrate the applicability of the scheme to a range of measurements of optical propagation characteristics is presented. Measurements include the chromatic dispersion of SMF-28 of lengths ranging from 1 m to 1 km, the nonlinear coefficient of highly nonlinear fiber and the phase transfer profile of an integrated optical ring resonator.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
A new form of interferometry combining high phase sensitivity and excellent mechanical isolation is proposed and demonstrated. These features arise from maintaining a probe and reference tone in the same medium under test at all times, their ultimate homodyne detection, as well as a novel method employing an optical programmable filter which is used to extract their relative phase difference. A compilation of studies performed to illustrate the applicability of the scheme to a range of measurements of optical propagation characteristics is presented. Measurements include the chromatic dispersion of SMF-28 of lengths ranging from 1 m to 1 km, the nonlinear coefficient of highly nonlinear fiber and the phase transfer profile of an integrated optical ring resonator. |
I Demirtzioglou, C Lacava, A Shakoor, A Khokhar, Y Jung, D J Thomson, P Petropoulos Apodized silicon photonic grating couplers for mode-order conversion Journal Article Photonics Research, 7 (9), pp. 1036–1041, 2019. Abstract | Links | Tags: coupler, intermodal, multimode, silicon, Silicon photonics, surface coupler, surface gratings @article{Demirtzioglou2019,
title = {Apodized silicon photonic grating couplers for mode-order conversion},
author = {I Demirtzioglou and C Lacava and A Shakoor and A Khokhar and Y Jung and D J Thomson and P Petropoulos},
doi = {10.1364/PRJ.7.001036},
year = {2019},
date = {2019-01-01},
journal = {Photonics Research},
volume = {7},
number = {9},
pages = {1036--1041},
abstract = {An out-of-plane silicon grating coupler capable of mode-order conversion at the chip–fiber interface is designed and fabricated. Optimization of the structure is performed through finite-difference time-domain simulations, and the final device is characterized through far-field profile and transmission measurements. A coupling loss of 3.1 dB to a commercial two-mode fiber is measured for a single TE0 → LP11 mode conversion grating, which includes a conversion penalty of 1.3 dB. Far-field patterns of the excited LP11 mode profile are also reported.},
keywords = {coupler, intermodal, multimode, silicon, Silicon photonics, surface coupler, surface gratings},
pubstate = {published},
tppubtype = {article}
}
An out-of-plane silicon grating coupler capable of mode-order conversion at the chip–fiber interface is designed and fabricated. Optimization of the structure is performed through finite-difference time-domain simulations, and the final device is characterized through far-field profile and transmission measurements. A coupling loss of 3.1 dB to a commercial two-mode fiber is measured for a single TE0 → LP11 mode conversion grating, which includes a conversion penalty of 1.3 dB. Far-field patterns of the excited LP11 mode profile are also reported. |
C Lacava, M A Ettabib, T D Bucio, G Sharp, A Z Khokhar, Y Jung, M Sorel, F Gardes, D J Richardson, P Petropoulos, P Petropoulos, F Parmigiani Intermodal bragg-scattering four wave mixing in silicon waveguides Journal Article Journal of Lightwave Technology, 37 (7), pp. 1680–1685, 2019. Abstract | Links | Tags: frequency generation, intermodal, intermodal four wave mixing, silicon, Silicon photonics, silicon-rich, wavelength conversion, wavelength converter @article{Lacava2019,
title = {Intermodal bragg-scattering four wave mixing in silicon waveguides},
author = {C Lacava and M A Ettabib and T D Bucio and G Sharp and A Z Khokhar and Y Jung and M Sorel and F Gardes and D J Richardson and P Petropoulos and P Petropoulos and F Parmigiani},
doi = {10.1109/JLT.2019.2901401},
year = {2019},
date = {2019-01-01},
journal = {Journal of Lightwave Technology},
volume = {37},
number = {7},
pages = {1680--1685},
abstract = {We demonstrate optical wavelength conversion in a multi-mode silicon waveguide using four wave mixing Bragg scattering enabled by a dual-pump CW scheme. The original signal and the generated idler pair excite one spatial mode (first, TE mode), while the two pumps excite a different spatial mode (second, TE mode) of the same waveguide. Our approach exploits the differences in the group velocities of the various supported spatial modes to ensure phase matching only for the desired nonlinear process. In this proof-of-principle experiment, any unintended idlers are generated with an extinction ratio up to 12 dB relative to the phase-matched idlers for a pumps-to-signal-idler-pair wavelength detuning of about 70 nm. The scalability of the scheme to achieve larger and multiple signal wavelength detunings from the pump frequencies is also discussed.},
keywords = {frequency generation, intermodal, intermodal four wave mixing, silicon, Silicon photonics, silicon-rich, wavelength conversion, wavelength converter},
pubstate = {published},
tppubtype = {article}
}
We demonstrate optical wavelength conversion in a multi-mode silicon waveguide using four wave mixing Bragg scattering enabled by a dual-pump CW scheme. The original signal and the generated idler pair excite one spatial mode (first, TE mode), while the two pumps excite a different spatial mode (second, TE mode) of the same waveguide. Our approach exploits the differences in the group velocities of the various supported spatial modes to ensure phase matching only for the desired nonlinear process. In this proof-of-principle experiment, any unintended idlers are generated with an extinction ratio up to 12 dB relative to the phase-matched idlers for a pumps-to-signal-idler-pair wavelength detuning of about 70 nm. The scalability of the scheme to achieve larger and multiple signal wavelength detunings from the pump frequencies is also discussed. |
A Xomalis, Y Jung, I Demirtzioglou, C Lacava, E Plum, D J Richardson, P Petropoulos, N I Zheludev Nonlinear control of coherent absorption and its optical signal processing applications Journal Article APL Photonics, 4 (10), 2019. Abstract | Links | Tags: nonlinear optics, wavelength conversion, wavelength converter @article{Xomalis2019,
title = {Nonlinear control of coherent absorption and its optical signal processing applications},
author = {A Xomalis and Y Jung and I Demirtzioglou and C Lacava and E Plum and D J Richardson and P Petropoulos and N I Zheludev},
doi = {10.1063/1.5123547},
year = {2019},
date = {2019-01-01},
journal = {APL Photonics},
volume = {4},
number = {10},
abstract = {All-optical data processing continues to attract significant interest as a way to overcome the electronic signal processing bottleneck of fiber telecommunication networks. Nonlinear optical devices such as limiters and saturable absorbers rely on intensity-dependent attenuation of light. However, making such devices using intensity-dependent multiphoton dissipation processes is an issue as these make complete absorption and transmission impossible. Here, we show that nonlinear phase retardation in an optical fiber can control the dissipation of coherent light waves interacting on a thin plasmonic absorber from total absorption to perfect transmission. The fiber's instantaneous Kerr nonlinearity and the femtosecond coherent absorption time scale make this approach ultrafast. We report proof-of-principle demonstrations of all-optical intensity discrimination, power limiting, pulse restoration, pulse splitting, and signal transfer between carrier wavelengths within a fiber circuit. Our results indicate that nonlinear control of coherent absorption can imitate and outperform saturable and multiphoton absorption in terms of bandwidth and contrast.},
keywords = {nonlinear optics, wavelength conversion, wavelength converter},
pubstate = {published},
tppubtype = {article}
}
All-optical data processing continues to attract significant interest as a way to overcome the electronic signal processing bottleneck of fiber telecommunication networks. Nonlinear optical devices such as limiters and saturable absorbers rely on intensity-dependent attenuation of light. However, making such devices using intensity-dependent multiphoton dissipation processes is an issue as these make complete absorption and transmission impossible. Here, we show that nonlinear phase retardation in an optical fiber can control the dissipation of coherent light waves interacting on a thin plasmonic absorber from total absorption to perfect transmission. The fiber's instantaneous Kerr nonlinearity and the femtosecond coherent absorption time scale make this approach ultrafast. We report proof-of-principle demonstrations of all-optical intensity discrimination, power limiting, pulse restoration, pulse splitting, and signal transfer between carrier wavelengths within a fiber circuit. Our results indicate that nonlinear control of coherent absorption can imitate and outperform saturable and multiphoton absorption in terms of bandwidth and contrast. |
A Xomalis, I Demirtzioglou, Y Jung, E Plum, C Lacava, P Petropoulos, D J Richardson, N I Zheludev Cryptography in coherent optical information networks using dissipative metamaterial gates Journal Article APL Photonics, 4 (4), 2019. Abstract | Links | Tags: nonlinear optics, nonlinear waveguides @article{Xomalis2019a,
title = {Cryptography in coherent optical information networks using dissipative metamaterial gates},
author = {A Xomalis and I Demirtzioglou and Y Jung and E Plum and C Lacava and P Petropoulos and D J Richardson and N I Zheludev},
doi = {10.1063/1.5092216},
year = {2019},
date = {2019-01-01},
journal = {APL Photonics},
volume = {4},
number = {4},
abstract = {All-optical encryption of information in fibre telecommunication networks offers lower complexity and far higher data rates than electronic encryption can deliver. However, existing optical layer encryption methods, which are compatible with keys of unlimited length, are based on nonlinear processes that require intense optical fields. Here, we introduce an optical layer secure communication protocol that does not rely on nonlinear optical processes but instead uses energy redistribution of coherent optical waves interacting on a plasmonic metamaterial absorber. We implement the protocol in a telecommunication optical fibre information network, where signal and key distribution lines use a common coherent information carrier. We investigate and demonstrate different encryption modes, including a scheme providing perfect secrecy. All-optical cryptography, as demonstrated here, exploits signal processing mechanisms that can satisfy optical telecom data rate requirements in any current or next-generation frequency band with bandwidth exceeding 100 THz and a switching energy of a few photons per bit. This is the first demonstration of an optical telecommunications application of metamaterial technology.},
keywords = {nonlinear optics, nonlinear waveguides},
pubstate = {published},
tppubtype = {article}
}
All-optical encryption of information in fibre telecommunication networks offers lower complexity and far higher data rates than electronic encryption can deliver. However, existing optical layer encryption methods, which are compatible with keys of unlimited length, are based on nonlinear processes that require intense optical fields. Here, we introduce an optical layer secure communication protocol that does not rely on nonlinear optical processes but instead uses energy redistribution of coherent optical waves interacting on a plasmonic metamaterial absorber. We implement the protocol in a telecommunication optical fibre information network, where signal and key distribution lines use a common coherent information carrier. We investigate and demonstrate different encryption modes, including a scheme providing perfect secrecy. All-optical cryptography, as demonstrated here, exploits signal processing mechanisms that can satisfy optical telecom data rate requirements in any current or next-generation frequency band with bandwidth exceeding 100 THz and a switching energy of a few photons per bit. This is the first demonstration of an optical telecommunications application of metamaterial technology. |
P Minzioni, C Lacava, T Tanabe, J Dong, X Hu, G Csaba, W Porod, G Singh, A E Willner, A Almaiman, J Laurat, J Nunn Roadmap on all-optical processing Journal Article Journal of Optics (United Kingdom), 21 (6), 2019. Abstract | Links | Tags: silicon nitride, Silicon photonics, surface coupler, transceiver, wavelength conversion, wavelength converter @article{Minzioni2019,
title = {Roadmap on all-optical processing},
author = {P Minzioni and C Lacava and T Tanabe and J Dong and X Hu and G Csaba and W Porod and G Singh and A E Willner and A Almaiman and J Laurat and J Nunn},
doi = {10.1088/2040-8986/ab0e66},
year = {2019},
date = {2019-01-01},
journal = {Journal of Optics (United Kingdom)},
volume = {21},
number = {6},
abstract = {The ability to process optical signals without passing into the electrical domain has always attracted the attention of the research community. Processing photons by photons unfolds new scenarios, in principle allowing for unseen signal processing and computing capabilities. Optical computation can be seen as a large scientific field in which researchers operate, trying to find solutions to their specific needs by different approaches; although the challenges can be substantially different, they are typically addressed using knowledge and technological platforms that are shared across the whole field. This significant know-how can also benefit other scientific communities, providing lateral solutions to their problems, as well as leading to novel applications. The aim of this Roadmap is to provide a broad view of the state-of-the-art in this lively scientific research field and to discuss the advances required to tackle emerging challenges, thanks to contributions authored by experts affiliated to both academic institutions and high-tech industries. The Roadmap is organized so as to put side by side contributions on different aspects of optical processing, aiming to enhance the cross-contamination of ideas between scientists working in three different fields of photonics: optical gates and logical units, high bit-rate signal processing and optical quantum computing. The ultimate intent of this paper is to provide guidance for young scientists as well as providing research-funding institutions and stake holders with a comprehensive overview of perspectives and opportunities offered by this research field.},
keywords = {silicon nitride, Silicon photonics, surface coupler, transceiver, wavelength conversion, wavelength converter},
pubstate = {published},
tppubtype = {article}
}
The ability to process optical signals without passing into the electrical domain has always attracted the attention of the research community. Processing photons by photons unfolds new scenarios, in principle allowing for unseen signal processing and computing capabilities. Optical computation can be seen as a large scientific field in which researchers operate, trying to find solutions to their specific needs by different approaches; although the challenges can be substantially different, they are typically addressed using knowledge and technological platforms that are shared across the whole field. This significant know-how can also benefit other scientific communities, providing lateral solutions to their problems, as well as leading to novel applications. The aim of this Roadmap is to provide a broad view of the state-of-the-art in this lively scientific research field and to discuss the advances required to tackle emerging challenges, thanks to contributions authored by experts affiliated to both academic institutions and high-tech industries. The Roadmap is organized so as to put side by side contributions on different aspects of optical processing, aiming to enhance the cross-contamination of ideas between scientists working in three different fields of photonics: optical gates and logical units, high bit-rate signal processing and optical quantum computing. The ultimate intent of this paper is to provide guidance for young scientists as well as providing research-funding institutions and stake holders with a comprehensive overview of perspectives and opportunities offered by this research field. |
2018
|
E Colusso, F De Ferrari, P Minzioni, A Martucci, Y Wang, F G Omenetto Engineering optical defects in biopolymer photonic lattices Journal Article Journal of Materials Chemistry C, 6 (5), pp. 966–971, 2018. Abstract | Links | Tags: @article{Colusso2018,
title = {Engineering optical defects in biopolymer photonic lattices},
author = {E Colusso and F {De Ferrari} and P Minzioni and A Martucci and Y Wang and F G Omenetto},
doi = {10.1039/c7tc04404f},
year = {2018},
date = {2018-01-01},
journal = {Journal of Materials Chemistry C},
volume = {6},
number = {5},
pages = {966--971},
abstract = {We report the design, fabrication and characterization of a silk inverse opal with engineered photonic bandgap. The realization of a controlled defect in the structure provides another step along the way to the realization of high-performance biocompatible and implantable optical components with programmable spectral responses that could be integrated with living material and suited for work in the biological therapeutic window.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
We report the design, fabrication and characterization of a silk inverse opal with engineered photonic bandgap. The realization of a controlled defect in the structure provides another step along the way to the realization of high-performance biocompatible and implantable optical components with programmable spectral responses that could be integrated with living material and suited for work in the biological therapeutic window. |
V Vitali, T Yang, P Minzioni Separation efficiency maximization in acoustofluidic systems: Study of the sample launch-position Journal Article RSC Advances, 8 (68), pp. 38955–38964, 2018. Abstract | Links | Tags: Microfluidic chip, Optofluidics @article{Vitali2018,
title = {Separation efficiency maximization in acoustofluidic systems: Study of the sample launch-position},
author = {V Vitali and T Yang and P Minzioni},
doi = {10.1039/c8ra08860h},
year = {2018},
date = {2018-01-01},
journal = {RSC Advances},
volume = {8},
number = {68},
pages = {38955--38964},
abstract = {The development of lab-on-chip microfluidic systems based on acoustic actuation, and in particular on the acoustophoretic force, has recently attracted significant attention from the scientific community thanks, in part, to the possibility of sample sorting on the basis of both geometrical and mechanical properties. It is commonly recognized that sample prefocusing and launch-position optimization have a substantial effect on the performance of these systems but a clear explanation of how these two parameters influence the system efficiency is still missing. In this manuscript we discuss the impact of both the sample launch position and the sample distribution at the input by the theoretical analysis of a simplified system and by numerical simulations of realistic configurations. The results show that the system performance can be greatly improved by selecting the proper microchannel dimensions and sample-launch position, offering relevant guidelines for the design of micro-acoustofluidic lab-on-chip devices.},
keywords = {Microfluidic chip, Optofluidics},
pubstate = {published},
tppubtype = {article}
}
The development of lab-on-chip microfluidic systems based on acoustic actuation, and in particular on the acoustophoretic force, has recently attracted significant attention from the scientific community thanks, in part, to the possibility of sample sorting on the basis of both geometrical and mechanical properties. It is commonly recognized that sample prefocusing and launch-position optimization have a substantial effect on the performance of these systems but a clear explanation of how these two parameters influence the system efficiency is still missing. In this manuscript we discuss the impact of both the sample launch position and the sample distribution at the input by the theoretical analysis of a simplified system and by numerical simulations of realistic configurations. The results show that the system performance can be greatly improved by selecting the proper microchannel dimensions and sample-launch position, offering relevant guidelines for the design of micro-acoustofluidic lab-on-chip devices. |
G Nava, T Yang, V Vitali, P Minzioni, I Cristiani, F Bragheri, R Osellame, L Bethge, S Klussmann, E M Paraboschi, R Asselta, T Bellini Newtonian to non-newtonian fluid transition of a model transient network Journal Article Soft Matter, 14 (17), pp. 3288–3295, 2018. Abstract | Links | Tags: @article{Nava2018,
title = {Newtonian to non-newtonian fluid transition of a model transient network},
author = {G Nava and T Yang and V Vitali and P Minzioni and I Cristiani and F Bragheri and R Osellame and L Bethge and S Klussmann and E M Paraboschi and R Asselta and T Bellini},
doi = {10.1039/c8sm00373d},
year = {2018},
date = {2018-01-01},
journal = {Soft Matter},
volume = {14},
number = {17},
pages = {3288--3295},
abstract = {The viscosity of gel-forming fluids is notoriously complex and its study can benefit from new model systems that enable a detailed control of the network features. Here we use a novel and simple microfluidic-based active microrheology approach to study the transition from Newtonian to non-Newtonian behavior in a DNA hydrogel whose structure, connectivity, density of bonds, bond energy and kinetics are strongly temperature dependent and well known. In a temperature range of 15 °C, the system reversibly and continuously transforms from a Newtonian dispersion of low-valence nanocolloids into a strongly shear-thinning fluid, passing through a set of intermediate states where it behaves as a power-law fluid. We demonstrate that the knowledge of network topology and bond free energy enables to quantitatively predict the observed behavior using established rheology models.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
The viscosity of gel-forming fluids is notoriously complex and its study can benefit from new model systems that enable a detailed control of the network features. Here we use a novel and simple microfluidic-based active microrheology approach to study the transition from Newtonian to non-Newtonian behavior in a DNA hydrogel whose structure, connectivity, density of bonds, bond energy and kinetics are strongly temperature dependent and well known. In a temperature range of 15 °C, the system reversibly and continuously transforms from a Newtonian dispersion of low-valence nanocolloids into a strongly shear-thinning fluid, passing through a set of intermediate states where it behaves as a power-law fluid. We demonstrate that the knowledge of network topology and bond free energy enables to quantitatively predict the observed behavior using established rheology models. |
A Xomalis, I Demirtzioglou, Y Jung, E Plum, C Lacava, P Petropoulos, D J Richardson, N I Zheludev Picosecond all-optical switching and dark pulse generation in a fibre-optic network using a plasmonic metamaterial absorber Journal Article Applied Physics Letters, 113 (5), 2018. Abstract | Links | Tags: @article{Xomalis2018,
title = {Picosecond all-optical switching and dark pulse generation in a fibre-optic network using a plasmonic metamaterial absorber},
author = {A Xomalis and I Demirtzioglou and Y Jung and E Plum and C Lacava and P Petropoulos and D J Richardson and N I Zheludev},
doi = {10.1063/1.5040829},
year = {2018},
date = {2018-01-01},
journal = {Applied Physics Letters},
volume = {113},
number = {5},
abstract = {Coherent interaction of two light waves on a film of subwavelength thickness provides remarkable opportunities for controlling intensity and polarization of light beams as well as all-optical image processing. Here, we show that such interactions can be used for optical dark pulse generation and basic all-optical signal processing in fully fiberized coherent information networks with 1 THz bandwidth. With an encapsulated plasmonic metamaterial absorber operating in the telecommunications C-band, we demonstrate switching and dark pulse generation with 1 ps laser pulses.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Coherent interaction of two light waves on a film of subwavelength thickness provides remarkable opportunities for controlling intensity and polarization of light beams as well as all-optical image processing. Here, we show that such interactions can be used for optical dark pulse generation and basic all-optical signal processing in fully fiberized coherent information networks with 1 THz bandwidth. With an encapsulated plasmonic metamaterial absorber operating in the telecommunications C-band, we demonstrate switching and dark pulse generation with 1 ps laser pulses. |
A Xomalis, I Demirtzioglou, E Plum, Y Jung, V Nalla, C Lacava, K F MacDonald, P Petropoulos, D J Richardson, N I Zheludev Fibre-optic metadevice for all-optical signal modulation based on coherent absorption Journal Article Nature Communications, 9 (1), 2018. Abstract | Links | Tags: @article{Xomalis2018a,
title = {Fibre-optic metadevice for all-optical signal modulation based on coherent absorption},
author = {A Xomalis and I Demirtzioglou and E Plum and Y Jung and V Nalla and C Lacava and K F MacDonald and P Petropoulos and D J Richardson and N I Zheludev},
doi = {10.1038/s41467-017-02434-y},
year = {2018},
date = {2018-01-01},
journal = {Nature Communications},
volume = {9},
number = {1},
abstract = {Recently, coherent control of the optical response of thin films in standing waves has attracted considerable attention, ranging from applications in excitation-selective spectroscopy and nonlinear optics to all-optical image processing. Here, we show that integration of metamaterial and optical fibre technologies allows the use of coherently controlled absorption in a fully fiberized and packaged switching metadevice. With this metadevice, which controls light with light in a nanoscale plasmonic metamaterial film on an optical fibre tip, we provide proof-of-principle demonstrations of logical functions XOR, NOT and AND that are performed within a coherent fibre network at wavelengths between 1530 and 1565 nm. The metadevice has been tested at up to 40 gigabits per second and sub-milliwatt power levels. Since coherent absorption can operate at the single-photon level and with 100 THz bandwidth, we argue that the demonstrated all-optical switch concept has potential applications in coherent and quantum information networks.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Recently, coherent control of the optical response of thin films in standing waves has attracted considerable attention, ranging from applications in excitation-selective spectroscopy and nonlinear optics to all-optical image processing. Here, we show that integration of metamaterial and optical fibre technologies allows the use of coherently controlled absorption in a fully fiberized and packaged switching metadevice. With this metadevice, which controls light with light in a nanoscale plasmonic metamaterial film on an optical fibre tip, we provide proof-of-principle demonstrations of logical functions XOR, NOT and AND that are performed within a coherent fibre network at wavelengths between 1530 and 1565 nm. The metadevice has been tested at up to 40 gigabits per second and sub-milliwatt power levels. Since coherent absorption can operate at the single-photon level and with 100 THz bandwidth, we argue that the demonstrated all-optical switch concept has potential applications in coherent and quantum information networks. |
I Demirtzioglou, C Lacava, K R H Bottrill, D J Thomson, G T Reed, D J Richardson, P Petropoulos Frequency comb generation in a silicon ring resonator modulator Journal Article Optics Express, 26 (2), pp. 790–797, 2018. Abstract | Links | Tags: comb generation, frequency conversion, frequency generation @article{Demirtzioglou2018,
title = {Frequency comb generation in a silicon ring resonator modulator},
author = {I Demirtzioglou and C Lacava and K R H Bottrill and D J Thomson and G T Reed and D J Richardson and P Petropoulos},
doi = {10.1364/OE.26.000790},
year = {2018},
date = {2018-01-01},
journal = {Optics Express},
volume = {26},
number = {2},
pages = {790--797},
abstract = {We report on the generation of an optical comb of highly uniform in power frequency lines (variation less than 0.7 dB) using a silicon ring resonator modulator. A characterization involving the measurement of the complex transfer function of the ring is presented and five frequency tones with a 10-GHz spacing are produced using a dual-frequency electrical input at 10 and 20 GHz. A comb shape comparison is conducted for different modulator bias voltages, indicating optimum operation at a small forward-bias voltage. A time-domain measurement confirmed that the comb signal was highly coherent, forming 20.3-ps-long pulses.},
keywords = {comb generation, frequency conversion, frequency generation},
pubstate = {published},
tppubtype = {article}
}
We report on the generation of an optical comb of highly uniform in power frequency lines (variation less than 0.7 dB) using a silicon ring resonator modulator. A characterization involving the measurement of the complex transfer function of the ring is presented and five frequency tones with a 10-GHz spacing are produced using a dual-frequency electrical input at 10 and 20 GHz. A comb shape comparison is conducted for different modulator bias voltages, indicating optimum operation at a small forward-bias voltage. A time-domain measurement confirmed that the comb signal was highly coherent, forming 20.3-ps-long pulses. |
2017
|
T Yang, G Nava, V Vitali, F Bragheri, R Osellame, T Bellini, I Cristiani, P Minzioni Integrated optofluidic chip for low-volume fluid viscosity measurement Journal Article Micromachines, 8 (3), 2017. Abstract | Links | Tags: Optofluidics @article{Yang2017,
title = {Integrated optofluidic chip for low-volume fluid viscosity measurement},
author = {T Yang and G Nava and V Vitali and F Bragheri and R Osellame and T Bellini and I Cristiani and P Minzioni},
doi = {10.3390/mi8030065},
year = {2017},
date = {2017-01-01},
journal = {Micromachines},
volume = {8},
number = {3},
abstract = {In the present work, an integrated optofluidic chip for fluid viscosity measurements in the range from 1 mPatextperiodcentereds to 100 mPatextperiodcentereds is proposed. The device allows the use of small sample volumes (textless 1 $mu$L) and the measurement of viscosity as a function of temperature. Thanks to the precise control of the force exerted on dielectric spheres by optical beams, the viscosity of fluids is assessed by comparing the experimentally observed movement of dielectric beads produced by the optical forces with that expected by numerical calculations. The chip and the developed technique are validated by analyzing several fluids, such as Milli-Q water, ethanol and water-glycerol mixtures. The results show a good agreement between the experimental values and those reported in the literature. The extremely reduced volume of the sample required and the high flexibility of this technique make it a good candidate for measuring a wide range of viscosity values as well as for the analysis of nonlinear viscosity in complex fluids.},
keywords = {Optofluidics},
pubstate = {published},
tppubtype = {article}
}
In the present work, an integrated optofluidic chip for fluid viscosity measurements in the range from 1 mPatextperiodcentereds to 100 mPatextperiodcentereds is proposed. The device allows the use of small sample volumes (textless 1 $mu$L) and the measurement of viscosity as a function of temperature. Thanks to the precise control of the force exerted on dielectric spheres by optical beams, the viscosity of fluids is assessed by comparing the experimentally observed movement of dielectric beads produced by the optical forces with that expected by numerical calculations. The chip and the developed technique are validated by analyzing several fluids, such as Milli-Q water, ethanol and water-glycerol mixtures. The results show a good agreement between the experimental values and those reported in the literature. The extremely reduced volume of the sample required and the high flexibility of this technique make it a good candidate for measuring a wide range of viscosity values as well as for the analysis of nonlinear viscosity in complex fluids. |
P Minzioni, R Osellame, C Sada, S Zhao, F G Omenetto, K B Gylfason, T Haraldsson, Y Zhang, A Ozcan, A Wax, D Erickson, D Sinton Roadmap for optofluidics Journal Article Journal of Optics (United Kingdom), 19 (9), 2017. Abstract | Links | Tags: Optofluidics, Roadmap @article{Minzioni2017,
title = {Roadmap for optofluidics},
author = {P Minzioni and R Osellame and C Sada and S Zhao and F G Omenetto and K B Gylfason and T Haraldsson and Y Zhang and A Ozcan and A Wax and D Erickson and D Sinton},
doi = {10.1088/2040-8986/aa783b},
year = {2017},
date = {2017-01-01},
journal = {Journal of Optics (United Kingdom)},
volume = {19},
number = {9},
abstract = {Optofluidics, nominally the research area where optics and fluidics merge, is a relatively new research field and it is only in the last decade that there has been a large increase in the number of optofluidic applications, as well as in the number of research groups, devoted to the topic. Nowadays optofluidics applications include, without being limited to, lab-on-a-chip devices, fluid-based and controlled lenses, optical sensors for fluids and for suspended particles, biosensors, imaging tools, etc. The long list of potential optofluidics applications, which have been recently demonstrated, suggests that optofluidic technologies will become more and more common in everyday life in the future, causing a significant impact on many aspects of our society. A characteristic of this research field, deriving from both its interdisciplinary origin and applications, is that in order to develop suitable solutions a combination of a deep knowledge in different fields, ranging from materials science to photonics, from microfluidics to molecular biology and biophysics, is often required. As a direct consequence, also being able to understand the long-term evolution of optofluidics research is not easy. In this article, we report several expert contributions on different topics so as to provide guidance for young scientists. At the same time, we hope that this document will also prove useful for funding institutions and stakeholders to better understand the perspectives and opportunities offered by this research field.},
keywords = {Optofluidics, Roadmap},
pubstate = {published},
tppubtype = {article}
}
Optofluidics, nominally the research area where optics and fluidics merge, is a relatively new research field and it is only in the last decade that there has been a large increase in the number of optofluidic applications, as well as in the number of research groups, devoted to the topic. Nowadays optofluidics applications include, without being limited to, lab-on-a-chip devices, fluid-based and controlled lenses, optical sensors for fluids and for suspended particles, biosensors, imaging tools, etc. The long list of potential optofluidics applications, which have been recently demonstrated, suggests that optofluidic technologies will become more and more common in everyday life in the future, causing a significant impact on many aspects of our society. A characteristic of this research field, deriving from both its interdisciplinary origin and applications, is that in order to develop suitable solutions a combination of a deep knowledge in different fields, ranging from materials science to photonics, from microfluidics to molecular biology and biophysics, is often required. As a direct consequence, also being able to understand the long-term evolution of optofluidics research is not easy. In this article, we report several expert contributions on different topics so as to provide guidance for young scientists. At the same time, we hope that this document will also prove useful for funding institutions and stakeholders to better understand the perspectives and opportunities offered by this research field. |
T Yang, Y Chen, P Minzioni A review on optical actuators for microfluidic systems Journal Article Journal of Micromechanics and Microengineering, 27 (12), 2017. Abstract | Links | Tags: Optofluidics @article{Yang2017a,
title = {A review on optical actuators for microfluidic systems},
author = {T Yang and Y Chen and P Minzioni},
doi = {10.1088/1361-6439/aa9207},
year = {2017},
date = {2017-01-01},
journal = {Journal of Micromechanics and Microengineering},
volume = {27},
number = {12},
abstract = {During the last few decades microfluidic systems have become more and more popular and their relevance in different fields is continually growing. In fact, the use of microchannels allows a significant reduction of the required sample-volume and opens the way to a completely new set of possible investigations, including the study of the properties of cells, the development of new cells' separation techniques and the analysis of single-cell proteins. One of the main differences between microscopic and macroscopic systems is obviously dictated by the need for suitable actuation mechanisms, which should allow precise control of microscopic fluid volumes and of micro-samples inside the fluid. Even if both syringe-pump and pneumatic-pump technologies significantly evolved and they currently enable sub-$mu$L samples control, completely new approaches were recently developed for the manipulation of samples inside the microchannel. This review is dedicated to describing different kinds of optical actuators that can be applied in microfluidic systems for sample manipulation as well as for pumping. The basic principles underlying the optical actuation mechanisms will be described first, and then several experimental demonstrations will be reviewed and compared.},
keywords = {Optofluidics},
pubstate = {published},
tppubtype = {article}
}
During the last few decades microfluidic systems have become more and more popular and their relevance in different fields is continually growing. In fact, the use of microchannels allows a significant reduction of the required sample-volume and opens the way to a completely new set of possible investigations, including the study of the properties of cells, the development of new cells' separation techniques and the analysis of single-cell proteins. One of the main differences between microscopic and macroscopic systems is obviously dictated by the need for suitable actuation mechanisms, which should allow precise control of microscopic fluid volumes and of micro-samples inside the fluid. Even if both syringe-pump and pneumatic-pump technologies significantly evolved and they currently enable sub-$mu$L samples control, completely new approaches were recently developed for the manipulation of samples inside the microchannel. This review is dedicated to describing different kinds of optical actuators that can be applied in microfluidic systems for sample manipulation as well as for pumping. The basic principles underlying the optical actuation mechanisms will be described first, and then several experimental demonstrations will be reviewed and compared. |
T Domínguez Bucio, A Z Khokhar, C Lacava, S Stankovic, G Z Mashanovich, P Petropoulos, F Y Gardes Material and optical properties of low-temperature NH3-free PECVD SiNx layers for photonic applications Journal Article Journal of Physics D: Applied Physics, 50 (2), 2017. Abstract | Links | Tags: nonlinear optics, nonlinear waveguides, silicon nitride, Silicon photonics, silicon-rich @article{DominguezBucio2017,
title = {Material and optical properties of low-temperature NH3-free PECVD SiNx layers for photonic applications},
author = {T {Domínguez Bucio} and A Z Khokhar and C Lacava and S Stankovic and G Z Mashanovich and P Petropoulos and F Y Gardes},
doi = {10.1088/1361-6463/50/2/025106},
year = {2017},
date = {2017-01-01},
journal = {Journal of Physics D: Applied Physics},
volume = {50},
number = {2},
abstract = {SiNx layers intended for photonic applications are typically fabricated using LPCVD and PECVD. These techniques rely on high-temperature processing (textgreater400 °C) to obtain low propagation losses. An alternative version of PECVD SiNx layers deposited at temperatures below 400 °C with a recipe that does not use ammonia (NH3-free PECVD) was previously demonstrated to be a good option to fabricate strip waveguides with propagation losses textless3 dB cm-1. We have conducted a systematic investigation of the influence of the deposition parameters on the material and optical properties of NH3-free PECVD SiNx layers fabricated at 350 °C using a design of experiments methodology. In particular, this paper discusses the effect of the SiH4 flow, RF power, chamber pressure and substrate on the structure, uniformity, roughness, deposition rate, refractive index, chemical composition, bond structure and H content of NH3-free PECVD SiNx layers. The results show that the properties and the propagation losses of the studied SiNx layers depend entirely on their compositional N/Si ratio, which is in fact the only parameter that can be directly tuned using the deposition parameters along with the film uniformity and deposition rate. These observations provide the means to optimise the propagation losses of the layers for photonic applications through the deposition parameters. In fact, we have been able to fabricate SiNx waveguides with H content textless20%, good uniformity and propagation losses of 1.5 dB cm-1 at 1550 nm and textless1 dB cm-1 at 1310 nm. As a result, this study can potentially help optimise the properties of the studied SiNx layers for different applications.},
keywords = {nonlinear optics, nonlinear waveguides, silicon nitride, Silicon photonics, silicon-rich},
pubstate = {published},
tppubtype = {article}
}
SiNx layers intended for photonic applications are typically fabricated using LPCVD and PECVD. These techniques rely on high-temperature processing (textgreater400 °C) to obtain low propagation losses. An alternative version of PECVD SiNx layers deposited at temperatures below 400 °C with a recipe that does not use ammonia (NH3-free PECVD) was previously demonstrated to be a good option to fabricate strip waveguides with propagation losses textless3 dB cm-1. We have conducted a systematic investigation of the influence of the deposition parameters on the material and optical properties of NH3-free PECVD SiNx layers fabricated at 350 °C using a design of experiments methodology. In particular, this paper discusses the effect of the SiH4 flow, RF power, chamber pressure and substrate on the structure, uniformity, roughness, deposition rate, refractive index, chemical composition, bond structure and H content of NH3-free PECVD SiNx layers. The results show that the properties and the propagation losses of the studied SiNx layers depend entirely on their compositional N/Si ratio, which is in fact the only parameter that can be directly tuned using the deposition parameters along with the film uniformity and deposition rate. These observations provide the means to optimise the propagation losses of the layers for photonic applications through the deposition parameters. In fact, we have been able to fabricate SiNx waveguides with H content textless20%, good uniformity and propagation losses of 1.5 dB cm-1 at 1550 nm and textless1 dB cm-1 at 1310 nm. As a result, this study can potentially help optimise the properties of the studied SiNx layers for different applications. |
M A Ettabib, C Lacava, Z Liu, A Bogris, A Kapsalis, M Brun, P Labeye, S Nicoletti, D Syvridis, D J Richardson, D J Richardson, P Petropoulos Wavelength conversion of complex modulation formats in a compact SiGe waveguide Journal Article Optics Express, 25 (4), pp. 3252–3258, 2017. Abstract | Links | Tags: frequency conversion, frequency generation, integrated optics, nonlinear optics, Silicon photonics, wavelength conversion @article{Ettabib2017,
title = {Wavelength conversion of complex modulation formats in a compact SiGe waveguide},
author = {M A Ettabib and C Lacava and Z Liu and A Bogris and A Kapsalis and M Brun and P Labeye and S Nicoletti and D Syvridis and D J Richardson and D J Richardson and P Petropoulos},
doi = {10.1364/OE.25.003252},
year = {2017},
date = {2017-01-01},
journal = {Optics Express},
volume = {25},
number = {4},
pages = {3252--3258},
abstract = {We report a nonlinear signal processing system based on a SiGe waveguide suitable for high spectral efficiency data signals. Four-wave-mixing (FWM)-based wavelength conversion of 10-Gbaud 16-Quadrature amplitude modulated (QAM) and 64-QAM signals is demonstrated with less than -10-dB conversion efficiency (CE), 36-dB idler optical signal-to-noise ratio (OSNR), negligible bit error ratio (BER) penalty and a 3-dB conversion bandwidth exceeding 30nm. The SiGe device was CW-pumped and operated in a passive scheme without giving rise to any two-photon absorption (TPA) effects.},
keywords = {frequency conversion, frequency generation, integrated optics, nonlinear optics, Silicon photonics, wavelength conversion},
pubstate = {published},
tppubtype = {article}
}
We report a nonlinear signal processing system based on a SiGe waveguide suitable for high spectral efficiency data signals. Four-wave-mixing (FWM)-based wavelength conversion of 10-Gbaud 16-Quadrature amplitude modulated (QAM) and 64-QAM signals is demonstrated with less than -10-dB conversion efficiency (CE), 36-dB idler optical signal-to-noise ratio (OSNR), negligible bit error ratio (BER) penalty and a 3-dB conversion bandwidth exceeding 30nm. The SiGe device was CW-pumped and operated in a passive scheme without giving rise to any two-photon absorption (TPA) effects. |
C Lacava, S Stankovic, A Khokhar, T Bucio, F Gardes, G Reed, D Richardson, P Petropoulos Si-rich Silicon Nitride for Nonlinear Signal Processing Applications Journal Article Scientific Reports, 7 (1), 2017. Abstract | Links | Tags: nonlinear optics, silicon nitride, Silicon photonics, silicon-rich @article{Lacava2017,
title = {Si-rich Silicon Nitride for Nonlinear Signal Processing Applications},
author = {C Lacava and S Stankovic and A Khokhar and T Bucio and F Gardes and G Reed and D Richardson and P Petropoulos},
doi = {10.1038/s41598-017-00062-6},
year = {2017},
date = {2017-01-01},
journal = {Scientific Reports},
volume = {7},
number = {1},
abstract = {Nonlinear silicon photonic devices have attracted considerable attention thanks to their ability to show large third-order nonlinear effects at moderate power levels allowing for all-optical signal processing functionalities in miniaturized components. Although significant efforts have been made and many nonlinear optical functions have already been demonstrated in this platform, the performance of nonlinear silicon photonic devices remains fundamentally limited at the telecom wavelength region due to the two photon absorption (TPA) and related effects. In this work, we propose an alternative CMOS-compatible platform, based on silicon-rich silicon nitride that can overcome this limitation. By carefully selecting the material deposition parameters, we show that both of the device linear and nonlinear properties can be tuned in order to exhibit the desired behaviour at the selected wavelength region. A rigorous and systematic fabrication and characterization campaign of different material compositions is presented, enabling us to demonstrate TPA-free CMOS-compatible waveguides with low linear loss (∼1.5 dB/cm) and enhanced Kerr nonlinear response (Re$gamma$ = 16 Wm-1). Thanks to these properties, our nonlinear waveguides are able to produce a $pi$ nonlinear phase shift, paving the way for the development of practical devices for future optical communication applications.},
keywords = {nonlinear optics, silicon nitride, Silicon photonics, silicon-rich},
pubstate = {published},
tppubtype = {article}
}
Nonlinear silicon photonic devices have attracted considerable attention thanks to their ability to show large third-order nonlinear effects at moderate power levels allowing for all-optical signal processing functionalities in miniaturized components. Although significant efforts have been made and many nonlinear optical functions have already been demonstrated in this platform, the performance of nonlinear silicon photonic devices remains fundamentally limited at the telecom wavelength region due to the two photon absorption (TPA) and related effects. In this work, we propose an alternative CMOS-compatible platform, based on silicon-rich silicon nitride that can overcome this limitation. By carefully selecting the material deposition parameters, we show that both of the device linear and nonlinear properties can be tuned in order to exhibit the desired behaviour at the selected wavelength region. A rigorous and systematic fabrication and characterization campaign of different material compositions is presented, enabling us to demonstrate TPA-free CMOS-compatible waveguides with low linear loss (∼1.5 dB/cm) and enhanced Kerr nonlinear response (Re$gamma$ = 16 Wm-1). Thanks to these properties, our nonlinear waveguides are able to produce a $pi$ nonlinear phase shift, paving the way for the development of practical devices for future optical communication applications. |
C Lacava, I Cardea, I Demirtzioglou, A E Khoja, L Ke, D J Thomson, X Ruan, F Zhang, G T Reed, D J Richardson, D J Richardson, P Petropoulos 49.6 Gb/s direct detection DMT transmission over 40 km single mode fibre using an electrically packaged silicon photonic modulator Journal Article Optics Express, 25 (24), pp. 29798–29811, 2017. Abstract | Links | Tags: DMT, Silicon photonics, spectral efficiency, transceiver @article{Lacava2017a,
title = {49.6 Gb/s direct detection DMT transmission over 40 km single mode fibre using an electrically packaged silicon photonic modulator},
author = {C Lacava and I Cardea and I Demirtzioglou and A E Khoja and L Ke and D J Thomson and X Ruan and F Zhang and G T Reed and D J Richardson and D J Richardson and P Petropoulos},
doi = {10.1364/OE.25.029798},
year = {2017},
date = {2017-01-01},
journal = {Optics Express},
volume = {25},
number = {24},
pages = {29798--29811},
abstract = {We present the characterization of a silicon Mach-Zehnder modulator with electrical packaging and show that it exhibits a large third-order intermodulation spurious-free dynamic range (textgreater 100 dB Hz2/3). This characteristic renders the modulator particularly suitable for the generation of high spectral e ciency discrete multi-tone signals and we experimentally demonstrate a single-channel, direct detection transmission system operating at 49.6 Gb/s, exhibiting a baseband spectral e ciency of 5 b/s/Hz. Successful transmission is demonstrated over various lengths of single mode fibre up to 40 km, without the need of any amplification or dispersion compensation.},
keywords = {DMT, Silicon photonics, spectral efficiency, transceiver},
pubstate = {published},
tppubtype = {article}
}
We present the characterization of a silicon Mach-Zehnder modulator with electrical packaging and show that it exhibits a large third-order intermodulation spurious-free dynamic range (textgreater 100 dB Hz2/3). This characteristic renders the modulator particularly suitable for the generation of high spectral e ciency discrete multi-tone signals and we experimentally demonstrate a single-channel, direct detection transmission system operating at 49.6 Gb/s, exhibiting a baseband spectral e ciency of 5 b/s/Hz. Successful transmission is demonstrated over various lengths of single mode fibre up to 40 km, without the need of any amplification or dispersion compensation. |
X Ruan, K Li, D J Thomson, C Lacava, F Meng, I Demirtzioglou, P Petropoulos, Y Zhu, G T Reed, F Zhang Experimental comparison of direct detection Nyquist SSB transmission based on silicon dual-drive and IQ Mach-Zehnder modulators with electrical packaging Journal Article Optics Express, 25 (16), pp. 19332–19342, 2017. Abstract | Links | Tags: 16 QAM, 4QAM, Silicon photonics @article{Ruan2017,
title = {Experimental comparison of direct detection Nyquist SSB transmission based on silicon dual-drive and IQ Mach-Zehnder modulators with electrical packaging},
author = {X Ruan and K Li and D J Thomson and C Lacava and F Meng and I Demirtzioglou and P Petropoulos and Y Zhu and G T Reed and F Zhang},
doi = {10.1364/OE.25.019332},
year = {2017},
date = {2017-01-01},
journal = {Optics Express},
volume = {25},
number = {16},
pages = {19332--19342},
abstract = {We have designed and fabricated a silicon photonic in-phase-quadrature (IQ) modulator based on a nested dual-drive Mach-Zehnder structure incorporating electrical packaging. We have assessed its use for generating Nyquist-shaped single sideband (SSB) signals by operating it either as an IQ Mach-Zehnder modulator (IQ-MZM) or using just a single branch of the dual-drive Mach-Zehnder modulator (DD-MZM). The impact of electrical packaging on the modulator bandwidth is also analyzed. We demonstrate 40 Gb/s (10Gbaud) 16-ary quadrature amplitude modulation (16-QAM) Nyquist-shaped SSB transmission over 160 km standard single mode fiber (SSMF). Without using any chromatic dispersion compensation, the bit error rates (BERs) of 5.4 × 10−4 and 9.0 × 10−5 were measured for the DD-MZM and IQ-MZM, respectively, far below the 7% hard-decision forward error correction threshold. The performance difference between IQ-MZM and DD-MZM is most likely due to the non-ideal electrical packaging. Our work is the first experimental comparison between silicon IQ-MZM and silicon DD-MZM in generating SSB signals. We also demonstrate 50 Gb/s (12.5Gbaud) 16-QAM Nyquist-shaped SSB transmission over 320 km SSMF with a BER of 2.7 × 10−3. Both the silicon IQ-MZM and the DD-MZM show potential for optical transmission at metro scale and for data center interconnection.},
keywords = {16 QAM, 4QAM, Silicon photonics},
pubstate = {published},
tppubtype = {article}
}
We have designed and fabricated a silicon photonic in-phase-quadrature (IQ) modulator based on a nested dual-drive Mach-Zehnder structure incorporating electrical packaging. We have assessed its use for generating Nyquist-shaped single sideband (SSB) signals by operating it either as an IQ Mach-Zehnder modulator (IQ-MZM) or using just a single branch of the dual-drive Mach-Zehnder modulator (DD-MZM). The impact of electrical packaging on the modulator bandwidth is also analyzed. We demonstrate 40 Gb/s (10Gbaud) 16-ary quadrature amplitude modulation (16-QAM) Nyquist-shaped SSB transmission over 160 km standard single mode fiber (SSMF). Without using any chromatic dispersion compensation, the bit error rates (BERs) of 5.4 × 10−4 and 9.0 × 10−5 were measured for the DD-MZM and IQ-MZM, respectively, far below the 7% hard-decision forward error correction threshold. The performance difference between IQ-MZM and DD-MZM is most likely due to the non-ideal electrical packaging. Our work is the first experimental comparison between silicon IQ-MZM and silicon DD-MZM in generating SSB signals. We also demonstrate 50 Gb/s (12.5Gbaud) 16-QAM Nyquist-shaped SSB transmission over 320 km SSMF with a BER of 2.7 × 10−3. Both the silicon IQ-MZM and the DD-MZM show potential for optical transmission at metro scale and for data center interconnection. |
R Marchetti, V Vitali, C Lacava, I Cristiani, G Giuliani, V Muffato, M Fournier, S Abrate, R Gaudino, E Temporiti, L Carroll, P Minzioni Low-loss micro-resonator filters fabricated in silicon by CMOS-compatible lithographic techniques: Design and characterization Journal Article Applied Sciences (Switzerland), 7 (2), 2017. Abstract | Links | Tags: @article{Marchetti2017,
title = {Low-loss micro-resonator filters fabricated in silicon by CMOS-compatible lithographic techniques: Design and characterization},
author = {R Marchetti and V Vitali and C Lacava and I Cristiani and G Giuliani and V Muffato and M Fournier and S Abrate and R Gaudino and E Temporiti and L Carroll and P Minzioni},
doi = {10.3390/app7020174},
year = {2017},
date = {2017-01-01},
journal = {Applied Sciences (Switzerland)},
volume = {7},
number = {2},
abstract = {Optical resonators are fundamental building-blocks for the development of Si-photonics-integrated circuits, as tunable on-chip optical filters. In addition to the specific spectral shape, which may vary according to a particular application, extremely low losses from these devices are a crucial requirement. In the current state-of-the-art devices, most low-loss filters have only been demonstrated by exploiting ad hoc lithographic and etching techniques, which are not compatible with the standard CMOS (complementary metal-oxide semiconductor) process-flow available at Si-photonic foundries. In this paper, we describe the design and optimization of optical micro-resonators, based on Si-waveguides with a height lower than the standard ones (i.e., less than 220 nm), prepared on SOI (silicon on insulator) platform, which allow the realization of high-performance optical filters with an insertion loss lower than 1 dB, using only previously validated lithographic etch-depths.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Optical resonators are fundamental building-blocks for the development of Si-photonics-integrated circuits, as tunable on-chip optical filters. In addition to the specific spectral shape, which may vary according to a particular application, extremely low losses from these devices are a crucial requirement. In the current state-of-the-art devices, most low-loss filters have only been demonstrated by exploiting ad hoc lithographic and etching techniques, which are not compatible with the standard CMOS (complementary metal-oxide semiconductor) process-flow available at Si-photonic foundries. In this paper, we describe the design and optimization of optical micro-resonators, based on Si-waveguides with a height lower than the standard ones (i.e., less than 220 nm), prepared on SOI (silicon on insulator) platform, which allow the realization of high-performance optical filters with an insertion loss lower than 1 dB, using only previously validated lithographic etch-depths. |
R Marchetti, V Vitali, C Lacava, I Cristiani, B Charbonnier, V Muffato, M Fournier, P Minzioni Group-velocity dispersion in SOI-based channel waveguides with reduced-height Journal Article Optics Express, 25 (9), pp. 9761–9767, 2017. Abstract | Links | Tags: @article{Marchetti2017a,
title = {Group-velocity dispersion in SOI-based channel waveguides with reduced-height},
author = {R Marchetti and V Vitali and C Lacava and I Cristiani and B Charbonnier and V Muffato and M Fournier and P Minzioni},
doi = {10.1364/OE.25.009761},
year = {2017},
date = {2017-01-01},
journal = {Optics Express},
volume = {25},
number = {9},
pages = {9761--9767},
abstract = {We report on the experimental characterization, in the telecom C-band, of group-velocity dispersion (D) in 100-nm high rectangular strip waveguides realized by silicon-on-insulator technology. We compare the experimental results with numerical predictions, showing that 100-nm high waveguides exhibit normal dispersion and that the absolute value of the dispersion coefficient D decreases as the waveguide width is increased. D at 1550 nm varies from -8130 to -3900 ps/(nmtextperiodcenteredkm) by increasing the waveguide width from 500 to 800 nm.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
We report on the experimental characterization, in the telecom C-band, of group-velocity dispersion (D) in 100-nm high rectangular strip waveguides realized by silicon-on-insulator technology. We compare the experimental results with numerical predictions, showing that 100-nm high waveguides exhibit normal dispersion and that the absolute value of the dispersion coefficient D decreases as the waveguide width is increased. D at 1550 nm varies from -8130 to -3900 ps/(nmtextperiodcenteredkm) by increasing the waveguide width from 500 to 800 nm. |
R Marchetti, C Lacava, A Khokhar, X Chen, I Cristiani, D J Richardson, G T Reed, P Petropoulos, P Minzioni High-efficiency grating-couplers: Demonstration of a new design strategy Journal Article Scientific Reports, 7 (1), 2017. Abstract | Links | Tags: @article{Marchetti2017b,
title = {High-efficiency grating-couplers: Demonstration of a new design strategy},
author = {R Marchetti and C Lacava and A Khokhar and X Chen and I Cristiani and D J Richardson and G T Reed and P Petropoulos and P Minzioni},
doi = {10.1038/s41598-017-16505-z},
year = {2017},
date = {2017-01-01},
journal = {Scientific Reports},
volume = {7},
number = {1},
abstract = {We present a simple and practical strategy that allows to design high-efficiency grating couplers. The technique is based on the simultaneous apodization of two structural parameters: the grating period and the fill-factor, along with the optimization of the grating coupler etching depth. Considering a 260 nm Si-thick Silicon-on-insulator platform, we numerically demonstrated a coupling efficiency of -0.8 dB (83%), well matching the experimental value of -0.9 dB (81%). Thanks to the optimized design, these results represent the best performance ever reported in the literature for SOI structures without the use of any back-reflector.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
We present a simple and practical strategy that allows to design high-efficiency grating couplers. The technique is based on the simultaneous apodization of two structural parameters: the grating period and the fill-factor, along with the optimization of the grating coupler etching depth. Considering a 260 nm Si-thick Silicon-on-insulator platform, we numerically demonstrated a coupling efficiency of -0.8 dB (83%), well matching the experimental value of -0.9 dB (81%). Thanks to the optimized design, these results represent the best performance ever reported in the literature for SOI structures without the use of any back-reflector. |
2016
|
C Langrock, R V Roussev, G Nava, P Minzioni, N Argiolas, C Sada, M M Fejer Nonlinear diffusion model for annealed proton-exchanged waveguides in zirconium-doped lithium niobate Journal Article Applied Optics, 55 (24), pp. 6559–6563, 2016. Abstract | Links | Tags: @article{Langrock2016,
title = {Nonlinear diffusion model for annealed proton-exchanged waveguides in zirconium-doped lithium niobate},
author = {C Langrock and R V Roussev and G Nava and P Minzioni and N Argiolas and C Sada and M M Fejer},
doi = {10.1364/AO.55.006559},
year = {2016},
date = {2016-01-01},
journal = {Applied Optics},
volume = {55},
number = {24},
pages = {6559--6563},
abstract = {Photorefractive-damage- (PRD) resistant zirconium-oxide-doped lithium niobate is investigated as a substrate for the realization of annealed proton-exchanged (APE) waveguides. Its advantages are a favorable distribution coefficient, PRD resistance comparable to magnesium-oxide-doped lithium niobate, and a proton-diffusion behavior resembling congruent lithium niobate. A 1D model for APE waveguides was developed based on a previous model for congruently melting lithium niobate. Evidence for a nonlinear index dependence on concentration was found.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Photorefractive-damage- (PRD) resistant zirconium-oxide-doped lithium niobate is investigated as a substrate for the realization of annealed proton-exchanged (APE) waveguides. Its advantages are a favorable distribution coefficient, PRD resistance comparable to magnesium-oxide-doped lithium niobate, and a proton-diffusion behavior resembling congruent lithium niobate. A 1D model for APE waveguides was developed based on a previous model for congruently melting lithium niobate. Evidence for a nonlinear index dependence on concentration was found. |
M Gazzetto, G Nava, A Zaltron, I Cristiani, C Sada, P Minzioni Numerical and experimental study of optoelectronic trapping on iron-doped lithium niobate substrate Journal Article Crystals, 6 (10), 2016. Abstract | Links | Tags: @article{Gazzetto2016,
title = {Numerical and experimental study of optoelectronic trapping on iron-doped lithium niobate substrate},
author = {M Gazzetto and G Nava and A Zaltron and I Cristiani and C Sada and P Minzioni},
doi = {10.3390/cryst6100123},
year = {2016},
date = {2016-01-01},
journal = {Crystals},
volume = {6},
number = {10},
abstract = {Optoelectronic tweezers (OET) are a promising technique for the realization of reconfigurable systems suitable to trap and manipulate microparticles. In particular, dielectrophoretic (DEP) forces produced by OET represent a valid alternative to micro-fabricated metal electrodes, as strong and spatially reconfigurable electrical fields can be induced in a photoconductive layer by means of light-driven phenomena. In this paper we report, and compare with the experimental data, the results obtained by analyzing the spatial configurations of the DEP-forces produced by a 532 nm laser beam, with Gaussian intensity distribution, impinging on a Fe-doped Lithium Niobate substrate. Furthermore, we also present a promising preliminary result for water-droplets trapping, which could open the way to the application of this technique to biological samples manipulation.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Optoelectronic tweezers (OET) are a promising technique for the realization of reconfigurable systems suitable to trap and manipulate microparticles. In particular, dielectrophoretic (DEP) forces produced by OET represent a valid alternative to micro-fabricated metal electrodes, as strong and spatially reconfigurable electrical fields can be induced in a photoconductive layer by means of light-driven phenomena. In this paper we report, and compare with the experimental data, the results obtained by analyzing the spatial configurations of the DEP-forces produced by a 532 nm laser beam, with Gaussian intensity distribution, impinging on a Fe-doped Lithium Niobate substrate. Furthermore, we also present a promising preliminary result for water-droplets trapping, which could open the way to the application of this technique to biological samples manipulation. |
T Yang, F Bragheri, P Minzioni A comprehensive review of optical stretcher for cell mechanical characterization at single-cell level Journal Article Micromachines, 7 (5), 2016. Abstract | Links | Tags: Optical tweezers @article{Yang2016,
title = {A comprehensive review of optical stretcher for cell mechanical characterization at single-cell level},
author = {T Yang and F Bragheri and P Minzioni},
doi = {10.3390/mi7050090},
year = {2016},
date = {2016-01-01},
journal = {Micromachines},
volume = {7},
number = {5},
abstract = {This paper presents a comprehensive review of the development of the optical stretcher, a powerful optofluidic device for single cell mechanical study by using optical force induced cell stretching. The different techniques and the different materials for the fabrication of the optical stretcher are first summarized. A short description of the optical-stretching mechanism is then given, highlighting the optical force calculation and the cell optical deformability characterization. Subsequently, the implementations of the optical stretcher in various cell-mechanics studies are shown on different types of cells. Afterwards, two new advancements on optical stretcher applications are also introduced: the active cell sorting based on cell mechanical characterization and the temperature effect on cell stretching measurement from laser-induced heating. Two examples of new functionalities developed with the optical stretcher are also included. Finally, the current major limitation and the future development possibilities are discussed.},
keywords = {Optical tweezers},
pubstate = {published},
tppubtype = {article}
}
This paper presents a comprehensive review of the development of the optical stretcher, a powerful optofluidic device for single cell mechanical study by using optical force induced cell stretching. The different techniques and the different materials for the fabrication of the optical stretcher are first summarized. A short description of the optical-stretching mechanism is then given, highlighting the optical force calculation and the cell optical deformability characterization. Subsequently, the implementations of the optical stretcher in various cell-mechanics studies are shown on different types of cells. Afterwards, two new advancements on optical stretcher applications are also introduced: the active cell sorting based on cell mechanical characterization and the temperature effect on cell stretching measurement from laser-induced heating. Two examples of new functionalities developed with the optical stretcher are also included. Finally, the current major limitation and the future development possibilities are discussed. |
T Yang, F Bragheri, G Nava, I Chiodi, C Mondello, R Osellame, K Berg-Sørensen, I Cristiani, P Minzioni A comprehensive strategy for the analysis of acoustic compressibility and optical deformability on single cells Journal Article Scientific Reports, 6 , 2016. Abstract | Links | Tags: Integrated, Microfluidic chip, Optofluidics @article{Yang2016a,
title = {A comprehensive strategy for the analysis of acoustic compressibility and optical deformability on single cells},
author = {T Yang and F Bragheri and G Nava and I Chiodi and C Mondello and R Osellame and K Berg-Sørensen and I Cristiani and P Minzioni},
doi = {10.1038/srep23946},
year = {2016},
date = {2016-01-01},
journal = {Scientific Reports},
volume = {6},
abstract = {We realized an integrated microfluidic chip that allows measuring both optical deformability and acoustic compressibility on single cells, by optical stretching and acoustophoresis experiments respectively. Additionally, we propose a measurement protocol that allows evaluating the experimental apparatus parameters before performing the cell-characterization experiments, including a non-destructive method to characterize the optical force distribution inside the microchannel. The chip was used to study important cell-mechanics parameters in two human breast cancer cell lines, MCF7 and MDA-MB231. Results indicate that MDA-MB231 has both higher acoustic compressibility and higher optical deformability than MCF7, but statistical analysis shows that optical deformability and acoustic compressibility are not correlated parameters. This result suggests the possibility to use them to analyze the response of different cellular structures. We also demonstrate that it is possible to perform both measurements on a single cell, and that the order of the two experiments does not affect the retrieved values.},
keywords = {Integrated, Microfluidic chip, Optofluidics},
pubstate = {published},
tppubtype = {article}
}
We realized an integrated microfluidic chip that allows measuring both optical deformability and acoustic compressibility on single cells, by optical stretching and acoustophoresis experiments respectively. Additionally, we propose a measurement protocol that allows evaluating the experimental apparatus parameters before performing the cell-characterization experiments, including a non-destructive method to characterize the optical force distribution inside the microchannel. The chip was used to study important cell-mechanics parameters in two human breast cancer cell lines, MCF7 and MDA-MB231. Results indicate that MDA-MB231 has both higher acoustic compressibility and higher optical deformability than MCF7, but statistical analysis shows that optical deformability and acoustic compressibility are not correlated parameters. This result suggests the possibility to use them to analyze the response of different cellular structures. We also demonstrate that it is possible to perform both measurements on a single cell, and that the order of the two experiments does not affect the retrieved values. |
C Lacava, M A Ettabib, I Cristiani, J M Fedeli, D J Richardson, P Petropoulos Ultra-Compact Amorphous Silicon Waveguide for Wavelength Conversion Journal Article IEEE Photonics Technology Letters, 28 (4), pp. 410–413, 2016. Abstract | Links | Tags: BSPK, nonlinear optics, QPSK, Silicon photonics, wavelength converter @article{Lacava2016,
title = {Ultra-Compact Amorphous Silicon Waveguide for Wavelength Conversion},
author = {C Lacava and M A Ettabib and I Cristiani and J M Fedeli and D J Richardson and P Petropoulos},
doi = {10.1109/LPT.2015.2496758},
year = {2016},
date = {2016-01-01},
journal = {IEEE Photonics Technology Letters},
volume = {28},
number = {4},
pages = {410--413},
abstract = {In this letter, we demonstrate, for the first time, successful four wave mixing (FWM)-based wavelength conversion of binary phase shift keyed (BPSK) and quadrature phase shift keyed (QPSK) signals, at 20-Gb/s bitrate, in a 1-mm long amorphous silicon waveguide. A maximum FWM-efficiency of -26 dB was achieved by employing a pump power of just 70 mW, establishing this technology as a contender for the development of ultra-compact, low power, silicon photonics wavelength converter. Bit error ratio measurements demonstrated successful conversion with less than 1 dB penalty level, for both BPSK and QPSK signals (at BER = 10-5).},
keywords = {BSPK, nonlinear optics, QPSK, Silicon photonics, wavelength converter},
pubstate = {published},
tppubtype = {article}
}
In this letter, we demonstrate, for the first time, successful four wave mixing (FWM)-based wavelength conversion of binary phase shift keyed (BPSK) and quadrature phase shift keyed (QPSK) signals, at 20-Gb/s bitrate, in a 1-mm long amorphous silicon waveguide. A maximum FWM-efficiency of -26 dB was achieved by employing a pump power of just 70 mW, establishing this technology as a contender for the development of ultra-compact, low power, silicon photonics wavelength converter. Bit error ratio measurements demonstrated successful conversion with less than 1 dB penalty level, for both BPSK and QPSK signals (at BER = 10-5). |
2015
|
R Martinez Vazquez, G Nava, M Veglione, T Yang, F Bragheri, P Minzioni, E Bianchi, M Di Tano, I Chiodi, R Osellame, C Mondello, I Cristiani An optofluidic constriction chip for monitoring metastatic potential and drug response of cancer cells Journal Article Integrative Biology (United Kingdom), 7 (4), pp. 477–484, 2015. Abstract | Links | Tags: Optofluidics @article{MartinezVazquez2015,
title = {An optofluidic constriction chip for monitoring metastatic potential and drug response of cancer cells},
author = {R {Martinez Vazquez} and G Nava and M Veglione and T Yang and F Bragheri and P Minzioni and E Bianchi and M {Di Tano} and I Chiodi and R Osellame and C Mondello and I Cristiani},
doi = {10.1039/c5ib00023h},
year = {2015},
date = {2015-01-01},
journal = {Integrative Biology (United Kingdom)},
volume = {7},
number = {4},
pages = {477--484},
abstract = {Cellular mechanical properties constitute good markers to characterize tumor cells, to study cell population heterogeneity and to highlight the effect of drug treatments. In this work, we describe the fabrication and validation of an integrated optofluidic chip capable of analyzing cellular deformability on the basis of the pressure gradient needed to push a cell through a narrow constriction. We demonstrate the ability of the chip to discriminate between tumorigenic and metastatic breast cancer cells (MCF7 and MDA-MB231) and between human melanoma cells with different metastatic potential (A375P and A375MC2). Moreover, we show that this chip allows highlighting the effect of drugs interfering with microtubule organization (paclitaxel, combretastatin A-4 and nocodazole) on cancer cells, which leads to changes in the pressure-gradient required to push cells through the constriction. Our single-cell microfluidic device for mechanical evaluation is compact and easy to use, allowing for an extensive use in different laboratory environments.},
keywords = {Optofluidics},
pubstate = {published},
tppubtype = {article}
}
Cellular mechanical properties constitute good markers to characterize tumor cells, to study cell population heterogeneity and to highlight the effect of drug treatments. In this work, we describe the fabrication and validation of an integrated optofluidic chip capable of analyzing cellular deformability on the basis of the pressure gradient needed to push a cell through a narrow constriction. We demonstrate the ability of the chip to discriminate between tumorigenic and metastatic breast cancer cells (MCF7 and MDA-MB231) and between human melanoma cells with different metastatic potential (A375P and A375MC2). Moreover, we show that this chip allows highlighting the effect of drugs interfering with microtubule organization (paclitaxel, combretastatin A-4 and nocodazole) on cancer cells, which leads to changes in the pressure-gradient required to push cells through the constriction. Our single-cell microfluidic device for mechanical evaluation is compact and easy to use, allowing for an extensive use in different laboratory environments. |
T Yang, P Paiè, G Nava, F Bragheri, R M Vazquez, P Minzioni, M Veglione, M Di Tano, C Mondello, R Osellame, R Osellame, I Cristiani An integrated optofluidic device for single-cell sorting driven by mechanical properties Journal Article Lab on a Chip, 15 (5), pp. 1262–1266, 2015. Abstract | Links | Tags: LabOnChip, Optofluidics @article{Yang2015,
title = {An integrated optofluidic device for single-cell sorting driven by mechanical properties},
author = {T Yang and P Pai{è} and G Nava and F Bragheri and R M Vazquez and P Minzioni and M Veglione and M {Di Tano} and C Mondello and R Osellame and R Osellame and I Cristiani},
doi = {10.1039/c4lc01496k},
year = {2015},
date = {2015-01-01},
journal = {Lab on a Chip},
volume = {15},
number = {5},
pages = {1262--1266},
abstract = {We present a novel optofluidic device for real-time sorting on the basis of cell mechanical properties, measured by optical stretching. The whole mechanism, based on optical forces, does not hamper the viability of the tested cells, which can be used for further analysis. The device effectiveness is demonstrated by extracting a sample population enriched with highly metastatic cells from a heterogeneous cell mixture.},
keywords = {LabOnChip, Optofluidics},
pubstate = {published},
tppubtype = {article}
}
We present a novel optofluidic device for real-time sorting on the basis of cell mechanical properties, measured by optical stretching. The whole mechanism, based on optical forces, does not hamper the viability of the tested cells, which can be used for further analysis. The device effectiveness is demonstrated by extracting a sample population enriched with highly metastatic cells from a heterogeneous cell mixture. |
C Liberale, G Cojoc, V Rajamanickam, L Ferrara, F Bragheri, P Minzioni, G Perozziello, P Candeloro, I Cristiani, E di Fabrizio Miniaturized optical tweezers through fiber-end microfabrication Book 2015. Abstract | Links | Tags: Optical tweezers, Optofluidics @book{Liberale2015,
title = {Miniaturized optical tweezers through fiber-end microfabrication},
author = {C Liberale and G Cojoc and V Rajamanickam and L Ferrara and F Bragheri and P Minzioni and G Perozziello and P Candeloro and I Cristiani and E di Fabrizio},
doi = {10.1007/978-3-319-06998-2_8},
year = {2015},
date = {2015-01-01},
booktitle = {Springer Series in Surface Sciences},
volume = {56},
pages = {159--180},
abstract = {Optical tweezers represent a powerful tool for a variety of applications both in biology and in physics, and their miniaturization and full integration is of great interest so as to reduce size (towards portable systems), and to minimize the required intervention from the operator. Optical fibers represent a natural solution to achieve this goal, and here we review the realization of single-fiber optical tweezers able to create a purely optical three-dimensional trap.},
keywords = {Optical tweezers, Optofluidics},
pubstate = {published},
tppubtype = {book}
}
Optical tweezers represent a powerful tool for a variety of applications both in biology and in physics, and their miniaturization and full integration is of great interest so as to reduce size (towards portable systems), and to minimize the required intervention from the operator. Optical fibers represent a natural solution to achieve this goal, and here we review the realization of single-fiber optical tweezers able to create a purely optical three-dimensional trap. |
T Yang, G Nava, P Minzioni, M Veglione, F Bragheri, F D Lelii, R M Vazquez, R Osellame, I Cristiani Investigation of temperature effect on cell mechanics by optofluidic microchips Journal Article Biomedical Optics Express, 6 (8), pp. 2991–2996, 2015. Abstract | Links | Tags: LabOnChip, Microfluidic chip, Optofluidics @article{Yang2015a,
title = {Investigation of temperature effect on cell mechanics by optofluidic microchips},
author = {T Yang and G Nava and P Minzioni and M Veglione and F Bragheri and F D Lelii and R M Vazquez and R Osellame and I Cristiani},
doi = {10.1364/BOE.6.002991},
year = {2015},
date = {2015-01-01},
journal = {Biomedical Optics Express},
volume = {6},
number = {8},
pages = {2991--2996},
abstract = {Here we present the results of a study concerning the effect of temperature on cell mechanical properties. Two different optofluidic microchips with external temperature control are used to investigate the temperature-induced changes of highly metastatic human melanoma cells (A375MC2) in the range of ~0 – 35 °C. By means of an integrated optical stretcher, we observe that cells' optical deformability is strongly enhanced by increasing cell and buffer-fluid temperature. This finding is supported by the results obtained from a second device, which probes the cells' ability to be squeezed through a constriction. Measured data demonstrate a marked dependence of cell mechanical properties on temperature, thus highlighting the importance of including a proper temperature-control system in the experimental apparatus.},
keywords = {LabOnChip, Microfluidic chip, Optofluidics},
pubstate = {published},
tppubtype = {article}
}
Here we present the results of a study concerning the effect of temperature on cell mechanical properties. Two different optofluidic microchips with external temperature control are used to investigate the temperature-induced changes of highly metastatic human melanoma cells (A375MC2) in the range of ~0 – 35 °C. By means of an integrated optical stretcher, we observe that cells' optical deformability is strongly enhanced by increasing cell and buffer-fluid temperature. This finding is supported by the results obtained from a second device, which probes the cells' ability to be squeezed through a constriction. Measured data demonstrate a marked dependence of cell mechanical properties on temperature, thus highlighting the importance of including a proper temperature-control system in the experimental apparatus. |
G Nava, F Bragheri, T Yang, P Minzioni, R Osellame, I Cristiani, K Berg-Sørensen All-silica microfluidic optical stretcher with acoustophoretic prefocusing Journal Article Microfluidics and Nanofluidics, 19 (4), pp. 837–844, 2015. Abstract | Links | Tags: Acoustophoresis, optical trapping @article{Nava2015,
title = {All-silica microfluidic optical stretcher with acoustophoretic prefocusing},
author = {G Nava and F Bragheri and T Yang and P Minzioni and R Osellame and I Cristiani and K Berg-Sørensen},
doi = {10.1007/s10404-015-1609-x},
year = {2015},
date = {2015-01-01},
journal = {Microfluidics and Nanofluidics},
volume = {19},
number = {4},
pages = {837--844},
abstract = {Acoustophoresis is a widely reported and used technique for microparticle manipulation and separation. In the study described here, acustophoresis is employed to prefocus the flow (i.e., focusing occurring upstream of the analysis region) in a microfluidic chip intended for optical trapping and stretching. The whole microchip is made of silica with optical waveguides integrated by femtosecond laser writing. The acoustic force is produced by driving an external piezoelectric ceramic attached underneath the microchip at the chip resonance frequency. Thanks to an efficient excitation of acoustic waves in both water and glass, acoustophoretic focusing is observed along the channel length (textgreater40 mm) and it is successfully demonstrated both with polystyrene beads, swollen red blood cell, and cells from mouse fibroblast cellular lines (L929). Moreover, by comparing results of cell stretching measurements, we demonstrate that acoustic waves do not alter the optical deformability of the cells and that the acoustic prefocusing results in a considerable enhancement of throughput in optical stretching experiments.},
keywords = {Acoustophoresis, optical trapping},
pubstate = {published},
tppubtype = {article}
}
Acoustophoresis is a widely reported and used technique for microparticle manipulation and separation. In the study described here, acustophoresis is employed to prefocus the flow (i.e., focusing occurring upstream of the analysis region) in a microfluidic chip intended for optical trapping and stretching. The whole microchip is made of silica with optical waveguides integrated by femtosecond laser writing. The acoustic force is produced by driving an external piezoelectric ceramic attached underneath the microchip at the chip resonance frequency. Thanks to an efficient excitation of acoustic waves in both water and glass, acoustophoretic focusing is observed along the channel length (textgreater40 mm) and it is successfully demonstrated both with polystyrene beads, swollen red blood cell, and cells from mouse fibroblast cellular lines (L929). Moreover, by comparing results of cell stretching measurements, we demonstrate that acoustic waves do not alter the optical deformability of the cells and that the acoustic prefocusing results in a considerable enhancement of throughput in optical stretching experiments. |
M J Strain, C Lacava, L Meriggi, I Cristiani, M Sorel Tunable Q-factor silicon microring resonators for ultra-low power parametric processes Journal Article Optics Letters, 40 (7), pp. 1274–1277, 2015. Abstract | Links | Tags: comb generation, integrated nonlinear photonics, nonlinear optics, Silicon photonics @article{Strain2015,
title = {Tunable Q-factor silicon microring resonators for ultra-low power parametric processes},
author = {M J Strain and C Lacava and L Meriggi and I Cristiani and M Sorel},
doi = {10.1364/OL.40.001274},
year = {2015},
date = {2015-01-01},
journal = {Optics Letters},
volume = {40},
number = {7},
pages = {1274--1277},
abstract = {A compact silicon ring resonator is demonstrated that allows simple electrical tuning of the ring coupling coefficient and Q-factor and therefore the resonant enhancement of on-chip nonlinear optical processes. Fabrication-induced variation in designed coupling fraction, crucial in the resonator performance, can be overcome using this postfabrication trimming technique. Tuning of the microring resonator across the critical coupling point is demonstrated, exhibiting a Q-factor tunable between 9000 and 96,000. Consequently, resonantly enhanced four-wave mixing shows tunable efficiency between -40 and -16.3 dB at an ultra-low on-chip pumppower of 0.7mW.},
keywords = {comb generation, integrated nonlinear photonics, nonlinear optics, Silicon photonics},
pubstate = {published},
tppubtype = {article}
}
A compact silicon ring resonator is demonstrated that allows simple electrical tuning of the ring coupling coefficient and Q-factor and therefore the resonant enhancement of on-chip nonlinear optical processes. Fabrication-induced variation in designed coupling fraction, crucial in the resonator performance, can be overcome using this postfabrication trimming technique. Tuning of the microring resonator across the critical coupling point is demonstrated, exhibiting a Q-factor tunable between 9000 and 96,000. Consequently, resonantly enhanced four-wave mixing shows tunable efficiency between -40 and -16.3 dB at an ultra-low on-chip pumppower of 0.7mW. |
A Bozzola, L Carroll, D Gerace, I Cristiani, L C Andreani Optimising apodized grating couplers in a pure SOI platform to -0.5 dB coupling efficiency Journal Article Optics Express, 23 (12), pp. 16289–16304, 2015. Abstract | Links | Tags: coupler, Silicon photonics, surface coupler, surface gratings @article{Bozzola2015,
title = {Optimising apodized grating couplers in a pure SOI platform to -0.5 dB coupling efficiency},
author = {A Bozzola and L Carroll and D Gerace and I Cristiani and L C Andreani},
doi = {10.1364/OE.23.016289},
year = {2015},
date = {2015-01-01},
journal = {Optics Express},
volume = {23},
number = {12},
pages = {16289--16304},
abstract = {We present a theoretical optimisation of 1D apodized grating couplers in a "pure" Silicon-On-Insulator (SOI) architecture, i.e. without any bottom reflector element, by means of a general mutative method. We perform a comprehensive 2D Finite Difference Time Domain study of chirped and apodized grating couplers in 220 nm SOI, and demonstrate that the global maximum coupling efficiency in that platform is capped to 65% (-1.9 dB). Moving to designs with thicker Si-layers, we identify a new record design in 340 nm SOI, with a simulated coupling efficiency of 89% (-0.5 dB). Going to thicker Si layers does not further improve the efficiency, implying that -0.5 dB may be a global maximum for a grating coupler in SOI without a bottom-reflector. Even after allowing for 193 nm UV-lithographic fabrication constraints, the 340 nm design still offers -0.7 dB efficiency. These new apodized designs are the first pure SOI couplers compatible with deep-UV lithography to offer better than -1 dB insertion losses.With only very minor changes to existing deposition and lithography recipes, they are compatible with the multi-project wafer runs already offered by Si-Photonics foundries.},
keywords = {coupler, Silicon photonics, surface coupler, surface gratings},
pubstate = {published},
tppubtype = {article}
}
We present a theoretical optimisation of 1D apodized grating couplers in a "pure" Silicon-On-Insulator (SOI) architecture, i.e. without any bottom reflector element, by means of a general mutative method. We perform a comprehensive 2D Finite Difference Time Domain study of chirped and apodized grating couplers in 220 nm SOI, and demonstrate that the global maximum coupling efficiency in that platform is capped to 65% (-1.9 dB). Moving to designs with thicker Si-layers, we identify a new record design in 340 nm SOI, with a simulated coupling efficiency of 89% (-0.5 dB). Going to thicker Si layers does not further improve the efficiency, implying that -0.5 dB may be a global maximum for a grating coupler in SOI without a bottom-reflector. Even after allowing for 193 nm UV-lithographic fabrication constraints, the 340 nm design still offers -0.7 dB efficiency. These new apodized designs are the first pure SOI couplers compatible with deep-UV lithography to offer better than -1 dB insertion losses.With only very minor changes to existing deposition and lithography recipes, they are compatible with the multi-project wafer runs already offered by Si-Photonics foundries. |
2014
|
P Pallavicini, A Donà, A Taglietti, P Minzioni, M Patrini, G Dacarro, G Chirico, L Sironi, N Bloise, L Visai, L Visai, L Scarabelli Self-assembled monolayers of gold nanostars: A convenient tool for near-IR photothermal biofilm eradication Journal Article Chemical Communications, 50 (16), pp. 1969–1971, 2014. Abstract | Links | Tags: @article{Pallavicini2014,
title = {Self-assembled monolayers of gold nanostars: A convenient tool for near-IR photothermal biofilm eradication},
author = {P Pallavicini and A Don{à} and A Taglietti and P Minzioni and M Patrini and G Dacarro and G Chirico and L Sironi and N Bloise and L Visai and L Visai and L Scarabelli},
doi = {10.1039/c3cc48667b},
year = {2014},
date = {2014-01-01},
journal = {Chemical Communications},
volume = {50},
number = {16},
pages = {1969--1971},
abstract = {Monolayers of gold nanostars (GNS) are grafted on mercaptopropyltrimethoxysilane-coated glass slides. In the formed monolayers the localized surface plasmon resonance of GNS can be tuned in the 700-1100 nm range. Upon laser excitation of the nearIR LSPR an efficient photothermal response is observed, inducing local hyperthermia and efficient killing of Staphylococcus aureus biofilms. textcopyright 2014 The Royal Society of Chemistry.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Monolayers of gold nanostars (GNS) are grafted on mercaptopropyltrimethoxysilane-coated glass slides. In the formed monolayers the localized surface plasmon resonance of GNS can be tuned in the 700-1100 nm range. Upon laser excitation of the nearIR LSPR an efficient photothermal response is observed, inducing local hyperthermia and efficient killing of Staphylococcus aureus biofilms. textcopyright 2014 The Royal Society of Chemistry. |
C Lacava, V Pusino, P Minzioni, M Sorel, I Cristiani Nonlinear properties of AlGaAs waveguides in continuous wave operation regime Journal Article Optics Express, 22 (5), pp. 5291–5298, 2014. Abstract | Links | Tags: @article{Lacava2014,
title = {Nonlinear properties of AlGaAs waveguides in continuous wave operation regime},
author = {C Lacava and V Pusino and P Minzioni and M Sorel and I Cristiani},
doi = {10.1364/OE.22.005291},
year = {2014},
date = {2014-01-01},
journal = {Optics Express},
volume = {22},
number = {5},
pages = {5291--5298},
abstract = {Aluminum Gallium Arsenide (AlGaAs) is an attractive platform for the development of integrated optical circuits for all-optical signal processing thanks to its large nonlinear coefficients in the 1.55-$mu$m telecommunication spectral region. In this paper we discuss the results of the nonlinear continuous-wave optical characterization of AlGaAs waveguides at a wavelength of 1.55 $mu$m. We also report the highest value ever reported in the literature for the real part of the nonlinear coefficient in this material (Re($gamma$) ≈521 W-1m-1). textcopyright 2014 Optical Society of America.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Aluminum Gallium Arsenide (AlGaAs) is an attractive platform for the development of integrated optical circuits for all-optical signal processing thanks to its large nonlinear coefficients in the 1.55-$mu$m telecommunication spectral region. In this paper we discuss the results of the nonlinear continuous-wave optical characterization of AlGaAs waveguides at a wavelength of 1.55 $mu$m. We also report the highest value ever reported in the literature for the real part of the nonlinear coefficient in this material (Re($gamma$) ≈521 W-1m-1). textcopyright 2014 Optical Society of America. |
L Carroll, D Gerace, I Cristiani, L C Andreani Optimizing polarization-diversity couplers for Si-photonics: Reaching the -1dB coupling efficiency threshold Journal Article Optics Express, 22 (12), pp. 14769–14781, 2014. Abstract | Links | Tags: Silicon photonics, surface coupler, surface gratings @article{Carroll2014,
title = {Optimizing polarization-diversity couplers for Si-photonics: Reaching the -1dB coupling efficiency threshold},
author = {L Carroll and D Gerace and I Cristiani and L C Andreani},
doi = {10.1364/OE.22.014769},
year = {2014},
date = {2014-01-01},
journal = {Optics Express},
volume = {22},
number = {12},
pages = {14769--14781},
abstract = {Polarization-diversity couplers are low-cost industrially-scalable passive devices that can couple light of unknown polarization from a telecom fiber-mode to a pair of TE-polarized wave-guided modes in the Silicon-on-Insulator platform. These couplers offer significantly more relaxed alignment tolerances than edge-coupling schemes, which is advantageous for commercial fiber-packaging of Si-photonic circuits. However, until now, polarization-diversity couplers have not offered sufficient coupling efficiency to motivate serious commercial consideration. Using 3D finite difference time domain calculations for device optimization, we identify Silicon-on-Insulator polarization-diversity couplers with 1550nm coupling efficiencies of 0.95dB and 1.9dB, for designs with and without bottom-reflector elements, respectively. These designs offer a significant improvement over state-of-the-art performance, and effectively bridge the "performance gap" between polarizationdiversity couplers and 1D-grating couplers. Our best polarization-diversity coupler design goes beyond the 1dB efficiency limit that is typically accepted as the minimum needed for industrial adoption of coupler devices in the telecoms market. textcopyright 2014 Optical Society of America.},
keywords = {Silicon photonics, surface coupler, surface gratings},
pubstate = {published},
tppubtype = {article}
}
Polarization-diversity couplers are low-cost industrially-scalable passive devices that can couple light of unknown polarization from a telecom fiber-mode to a pair of TE-polarized wave-guided modes in the Silicon-on-Insulator platform. These couplers offer significantly more relaxed alignment tolerances than edge-coupling schemes, which is advantageous for commercial fiber-packaging of Si-photonic circuits. However, until now, polarization-diversity couplers have not offered sufficient coupling efficiency to motivate serious commercial consideration. Using 3D finite difference time domain calculations for device optimization, we identify Silicon-on-Insulator polarization-diversity couplers with 1550nm coupling efficiencies of 0.95dB and 1.9dB, for designs with and without bottom-reflector elements, respectively. These designs offer a significant improvement over state-of-the-art performance, and effectively bridge the "performance gap" between polarizationdiversity couplers and 1D-grating couplers. Our best polarization-diversity coupler design goes beyond the 1dB efficiency limit that is typically accepted as the minimum needed for industrial adoption of coupler devices in the telecoms market. textcopyright 2014 Optical Society of America. |