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. |
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. |
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. |
2017
|
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. |
2016
|
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
|
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
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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. |