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. |
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. |
