Optical pump-rejection filter based on silicon sub-wavelength engineered photonic structures

The high index contrast of the silicon-on-insulator (SOI) platform allows the realization of ultra-compact photonic circuits. However, this high contrast hinders the implementation of narrow-band Bragg filters. These typically require corrugations widths of a few nanometers or double-etch geometries, hampering device fabrication. Here we report, for the first time, on the realization of SOI Bragg filters based on sub-wavelength index engineering in a differential corrugation width configuration. The proposed double periodicity structure allows narrow-band rejection with a single etch step and relaxed width constraints. Based on this concept, we experimentally demonstrate a single-etch, $\mathbf{220\,nm}$ thick, Si Bragg filter featuring a corrugation width of $\mathbf{150\,nm}$, a rejection bandwidth of $\mathbf{1.1\,nm}$ and an extinction ratio exceeding $\mathbf{40\,dB}$. This represents a ten-fold width increase compared to conventional single-periodicity, single-etch counterparts with similar bandwidths

Generation and manipulation of entangled photonic states for quantum communication and metrology

Après une première révolution quantique marquée par l'avènement de la physique quantique et de ses lois contre-intuitives, le monde du XXIe siècle est en proie à une seconde révolution articulée autour des technologies quantiques. Ces dernières promettent un bouleversement important dans les domaines de la communication, du calcul, de la simulation et de la métrologie. Dans cette thèse, nous abordons deux des quatre sous-domaines cités précédemment, à savoir ceux de la communication et de la métrologie quantique. Le mot d'ordre rassemblant ces travaux est l'intrication. En effet, nous montrons que, grâce à cette propriété fondamentale, les performances des systèmes de communication et de métrologie standards peuvent être surpassés. Ainsi, nous présentons comment générer ces états intriqués responsables de l'avantage quantique, et ce sur différentes plateformes technologiques. La première plateforme exploitée est le silicium. Récente pour la photonique, elle combine des avantages de maturité permettant l'intégration de nombreuses structures micrométriques sur une même puce, avec des propriétés non-linéaires, basés sur des processus d'ordre 3, efficaces. Le silicium se destine alors à de nombreuses applications comme nous le montrons en générant des paires de photons intriqués démultiplexés spectralement et directement compatibles avec les réseaux de télécommunications standards. La seconde plateforme que nous présentons est le niobate de lithium. Cette dernière, très exploitée dans bon nombres de travaux en photonique quantique, possède une efficacité de génération de paires de photons intriqués très importante, notamment grâce à l'exploitation de processus non-linéaires d'ordre 2. Nous détaillons une expérience de génération d'états hyper-intriqués, qui, à l'instar du silicium, est orientée vers le domaine de la communication quantique. Enfin, nous exploitons aussi ces paires de photons intriqués combinés à des méthodes d'interférométrie quantique afin de réaliser une expérience de métrologie quantique. Le but de cette dernière étant de mesurer avec une précision inédite la différence d'indices de réfraction de fibres bi-coeurs.After a first quantum revolution marked by the advent of quantum physics and its counter-intuitive laws, the XXIst century is in the throes of a second quantum revolution based on quantum technologies. These promises a major upheaval in the areas of communication, calculation, simulation and metrology. In this thesis, we address two of the four subdomains mentioned above, namely those of communication and quantum metrology. The main word bringing together these works is entanglement. Indeed, we show that, thanks to this fundamental property, the performances of standard communication and metrology systems can be surpassed. Thus, we present how to generate these entangled states responsible for the quantum advantage, and this on two technological platforms. The first platform exploited is silicon. The latter, recent for photonics, combines the advantages of maturity allowing the integration of many micrometric structures on the same chip, with efficient non-linear properties, based on third order process. Silicon is then destined for many applications as we show by generating pairs of spectrally demultiplexed entangled photons directly compatible with standard telecommunication networks. The second platform we present is lithium niobate. The latter, widely used in many quantum photonics demonstrations, has a very important efficiency of entangled photon pairs generation, notably thanks to the exploitation of second order non-linear process. We detail an experiment of hyper-entangled states generation, which, like silicon, is oriented towards the domain of quantum communication. Finally, we also exploit these pairs of entangled photons combined with quantum interferometry methods to realize a quantum metrology experiment. The purpose is to measure with unprecedented precision the refractive indices difference of dual-core fibers

Génération et manipulation d'états photoniques intriqués pour la communication et la métrologie quantiques

After a first quantum revolution marked by the advent of quantum physics and its counter-intuitive laws, the XXIst century is in the throes of a second quantum revolution based on quantum technologies. These promises a major upheaval in the areas of communication, calculation, simulation and metrology. In this thesis, we address two of the four subdomains mentioned above, namely those of communication and quantum metrology. The main word bringing together these works is entanglement. Indeed, we show that, thanks to this fundamental property, the performances of standard communication and metrology systems can be surpassed. Thus, we present how to generate these entangled states responsible for the quantum advantage, and this on two technological platforms. The first platform exploited is silicon. The latter, recent for photonics, combines the advantages of maturity allowing the integration of many micrometric structures on the same chip, with efficient non-linear properties, based on third order process. Silicon is then destined for many applications as we show by generating pairs of spectrally demultiplexed entangled photons directly compatible with standard telecommunication networks. The second platform we present is lithium niobate. The latter, widely used in many quantum photonics demonstrations, has a very important efficiency of entangled photon pairs generation, notably thanks to the exploitation of second order non-linear process. We detail an experiment of hyper-entangled states generation, which, like silicon, is oriented towards the domain of quantum communication. Finally, we also exploit these pairs of entangled photons combined with quantum interferometry methods to realize a quantum metrology experiment. The purpose is to measure with unprecedented precision the refractive indices difference of dual-core fibers.Après une première révolution quantique marquée par l'avènement de la physique quantique et de ses lois contre-intuitives, le monde du XXIe siècle est en proie à une seconde révolution articulée autour des technologies quantiques. Ces dernières promettent un bouleversement important dans les domaines de la communication, du calcul, de la simulation et de la métrologie. Dans cette thèse, nous abordons deux des quatre sous-domaines cités précédemment, à savoir ceux de la communication et de la métrologie quantique. Le mot d'ordre rassemblant ces travaux est l'intrication. En effet, nous montrons que, grâce à cette propriété fondamentale, les performances des systèmes de communication et de métrologie standards peuvent être surpassés. Ainsi, nous présentons comment générer ces états intriqués responsables de l'avantage quantique, et ce sur différentes plateformes technologiques. La première plateforme exploitée est le silicium. Récente pour la photonique, elle combine des avantages de maturité permettant l'intégration de nombreuses structures micrométriques sur une même puce, avec des propriétés non-linéaires, basés sur des processus d'ordre 3, efficaces. Le silicium se destine alors à de nombreuses applications comme nous le montrons en générant des paires de photons intriqués démultiplexés spectralement et directement compatibles avec les réseaux de télécommunications standards. La seconde plateforme que nous présentons est le niobate de lithium. Cette dernière, très exploitée dans bon nombres de travaux en photonique quantique, possède une efficacité de génération de paires de photons intriqués très importante, notamment grâce à l'exploitation de processus non-linéaires d'ordre 2. Nous détaillons une expérience de génération d'états hyper-intriqués, qui, à l'instar du silicium, est orientée vers le domaine de la communication quantique. Enfin, nous exploitons aussi ces paires de photons intriqués combinés à des méthodes d'interférométrie quantique afin de réaliser une expérience de métrologie quantique. Le but de cette dernière étant de mesurer avec une précision inédite la différence d'indices de réfraction de fibres bi-coeurs

Polarization selective ultra-braodband wavelength conversion in silicon nitride waveguide

We report broadband continuous-wave frequency conversion from the O-band (1.33 μm) to the short-wave infrared (2.6 μm) in a 50 cm long low-loss Si3N4 waveguide, leveraging polarization selective far-detuned phase matching

Thermally resilient depressed-index core fully-aperiodic-large-pitch fiber for high average power operation (Conference Presentation)

International audienc

Quantum-limited determination of refractive index difference by means of entanglement

International audienceShaping single-mode operation in high-power fibers requires a precise knowledge of the gain-medium optical properties. This requires precise measurements of the refractive index differences (Δn) between the core and the cladding of the fiber. We exploit a quantum optical method based on low-coherence Hong-Ou-Mandel interferometry to perform practical measurements of the refractive index difference using broadband energy-time entangled photons. The precision enhancement reached with this method is benchmarked with a classical method based on single photon interferometry. We show in classical regime an improvement by an order of magnitude of the precision compared to already reported classical methods. Strikingly, in the quantum regime, we demonstrate an extra factor of 4 on the precision enhancement, exhibiting a state-of-the-art Δn precision of 6 × 10$^{−7}$. This work sets the quantum photonics metrology as a powerful characterization tool that should enable a faster and reliable design of materials dedicated to light amplification

Coherency‐Broken Bragg Filters: Overcoming On‐Chip Rejection Limitations

[EN] Selective optical filters with high rejection levels are of fundamental importance for a wide range of advanced photonic circuits. However, the implementation of high-rejection on-chip optical filters is seriously hampered by phase errors arising from fabrication imperfections. Due to coherent interactions, unwanted phase-shifts result in detrimental destructive interferences that distort the filter response, whatever the chosen strategy (resonators, interferometers, Bragg filters, etc.). State-of-the-art high-rejection filters partially circumvent the sensitivity to phase errors by means of active tuning, complicating device fabrication and operation. Here, a new approach based on coherency-broken Bragg filters is proposed to overcome this fundamental limitation. Non-coherent interaction among modal-engineered waveguide Bragg gratings separated by single-mode waveguides is exploited to yield effective cascading, even in the presence of phase errors. This technologically independent approach allows seamless combination of filter stages with moderate performance free of active control, providing a dramatic increase of on-chip rejection. Based on this concept, on-chip non-coherent cascading of Si Bragg filters is experimentally demonstrated, achieving a light rejection exceeding 80 dB, the largest value reported for an all-passive silicon filter.This work has been partially funded by the Agence Nationale de la Recherche (ANR-SITQOM-15-CE24-0005, ANR-MIRSPEC-17-CE09-0041) and the H2020 European Research Council (ERC) (ERC POPSTAR 647342). The fabrication of the device was performed at the Plateforme de Micro-Nano-Technologie/C2N, which is partially funded by the Conseil Général de l'Essonne. This work was partly supported by the French RENATECH network.Oser, D.; Mazeas, F.; Le Roux, X.; Pérez-Galacho, D.; Alibart, O.; Tanzilli, S.; Labonté, L.... (2019). Coherency-Broken Bragg Filters: Overcoming On-Chip Rejection Limitations. Laser & Photonics Review. 13(8):1-8. https://doi.org/10.1002/lpor.20180022618138Fernández Gavela, A., Grajales García, D., Ramirez, J., & Lechuga, L. (2016). Last Advances in Silicon-Based Optical Biosensors. Sensors, 16(3), 285. doi:10.3390/s16030285Knill, E., Laflamme, R., & Milburn, G. J. (2001). A scheme for efficient quantum computation with linear optics. Nature, 409(6816), 46-52. doi:10.1038/35051009Cheben, P., Schmid, J. H., Wang, S., Xu, D.-X., Vachon, M., Janz, S., … Picard, M.-J. (2015). Broadband polarization independent nanophotonic coupler for silicon waveguides with ultra-high efficiency. Optics Express, 23(17), 22553. doi:10.1364/oe.23.022553Ziebell, M., Marris-Morini, D., Rasigade, G., Fédéli, J.-M., Crozat, P., Cassan, E., … Vivien, L. (2012). 40 Gbit/s low-loss silicon optical modulator based on a pipin diode. Optics Express, 20(10), 10591. doi:10.1364/oe.20.010591Vivien, L., Polzer, A., Marris-Morini, D., Osmond, J., Hartmann, J. M., Crozat, P., … Fédéli, J. M. (2012). Zero-bias 40Gbit/s germanium waveguide photodetector on silicon. Optics Express, 20(2), 1096. doi:10.1364/oe.20.001096Jouguet, P., Kunz-Jacques, S., Leverrier, A., Grangier, P., & Diamanti, E. (2013). Experimental demonstration of long-distance continuous-variable quantum key distribution. Nature Photonics, 7(5), 378-381. doi:10.1038/nphoton.2013.63Azzini, S., Grassani, D., Strain, M. J., Sorel, M., Helt, L. G., Sipe, J. E., … Bajoni, D. (2012). Ultra-low power generation of twin photons in a compact silicon ring resonator. Optics Express, 20(21), 23100. doi:10.1364/oe.20.023100Jiang, W. C., Lu, X., Zhang, J., Painter, O., & Lin, Q. (2015). Silicon-chip source of bright photon pairs. Optics Express, 23(16), 20884. doi:10.1364/oe.23.020884Grassani, D., Azzini, S., Liscidini, M., Galli, M., Strain, M. J., Sorel, M., … Bajoni, D. (2015). Micrometer-scale integrated silicon source of time-energy entangled photons. Optica, 2(2), 88. doi:10.1364/optica.2.000088Piekarek, M., Bonneau, D., Miki, S., Yamashita, T., Fujiwara, M., Sasaki, M., … Thompson, M. G. (2017). High-extinction ratio integrated photonic filters for silicon quantum photonics. Optics Letters, 42(4), 815. doi:10.1364/ol.42.000815Klitis, C., Cantarella, G., Strain, M. J., & Sorel, M. (2017). High-extinction-ratio TE/TM selective Bragg grating filters on silicon-on-insulator. Optics Letters, 42(15), 3040. doi:10.1364/ol.42.003040Xia, F., Rooks, M., Sekaric, L., & Vlasov, Y. (2007). Ultra-compact high order ring resonator filters using submicron silicon photonic wires for on-chip optical interconnects. Optics Express, 15(19), 11934. doi:10.1364/oe.15.011934Zou, Z., Zhou, L., Wang, M., Wu, K., & Chen, J. (2016). Tunable spiral Bragg gratings in 60-nm-thick silicon-on-insulator strip waveguides. Optics Express, 24(12), 12831. doi:10.1364/oe.24.012831Lu, Z., Jhoja, J., Klein, J., Wang, X., Liu, A., Flueckiger, J., … Chrostowski, L. (2017). Performance prediction for silicon photonics integrated circuits with layout-dependent correlated manufacturing variability. Optics Express, 25(9), 9712. doi:10.1364/oe.25.009712Vengsarkar, A. M., Lemaire, P. J., Judkins, J. B., Bhatia, V., Erdogan, T., & Sipe, J. E. (1996). Long-period fiber gratings as band-rejection filters. Journal of Lightwave Technology, 14(1), 58-65. doi:10.1109/50.476137Litchinitser, N. M., Eggleton, B. J., & Agrawal, G. P. (1998). Dispersion of cascaded fiber gratings in WDM lightwave systems. Journal of Lightwave Technology, 16(8), 1523-1529. doi:10.1109/50.704620Ong, J. R., Kumar, R., & Mookherjea, S. (2013). Ultra-High-Contrast and Tunable-Bandwidth Filter Using Cascaded High-Order Silicon Microring Filters. IEEE Photonics Technology Letters, 25(16), 1543-1546. doi:10.1109/lpt.2013.2267539Cooper, M. L., Gupta, G., Schneider, M. A., Green, W. M. J., Assefa, S., Xia, F., … Mookherjea, S. (2010). Statistics of light transport in 235-ring silicon coupled-resonator optical waveguides. Optics Express, 18(25), 26505. doi:10.1364/oe.18.026505Y.Painchaud M.Poulin C.Latrasse M.‐J.Picard presented atInt. Conf. on Group IV Photonics IEEE San Diego CA USA August2012 pap. 13058915.FDTD solutions Lumerical Solutions Inc. http://www.lumerical.com.Yariv, A. (1973). Coupled-mode theory for guided-wave optics. IEEE Journal of Quantum Electronics, 9(9), 919-933. doi:10.1109/jqe.1973.1077767Wang, X., Wang, Y., Flueckiger, J., Bojko, R., Liu, A., Reid, A., … Chrostowski, L. (2014). Precise control of the coupling coefficient through destructive interference in silicon waveguide Bragg gratings. Optics Letters, 39(19), 5519. doi:10.1364/ol.39.005519Qiu, H., Jiang, J., Yu, P., Dai, T., Yang, J., Yu, H., & Jiang, X. (2016). Silicon band-rejection and band-pass filter based on asymmetric Bragg sidewall gratings in a multimode waveguide. Optics Letters, 41(11), 2450. doi:10.1364/ol.41.002450Cheben, P., Halir, R., Schmid, J. H., Atwater, H. A., & Smith, D. R. (2018). Subwavelength integrated photonics. Nature, 560(7720), 565-572. doi:10.1038/s41586-018-0421-7Simard, A. D., Belhadj, N., Painchaud, Y., & LaRochelle, S. (2012). Apodized Silicon-on-Insulator Bragg Gratings. IEEE Photonics Technology Letters, 24(12), 1033-1035. doi:10.1109/lpt.2012.2194278Wang, X., Shi, W., Yun, H., Grist, S., Jaeger, N. A. F., & Chrostowski, L. (2012). Narrow-band waveguide Bragg gratings on SOI wafers with CMOS-compatible fabrication process. Optics Express, 20(14), 15547. doi:10.1364/oe.20.015547Halir, R., Cheben, P., Janz, S., Xu, D.-X., Molina-Fernández, Í., & Wangüemert-Pérez, J. G. (2009). Waveguide grating coupler with subwavelength microstructures. Optics Letters, 34(9), 1408. doi:10.1364/ol.34.001408Benedikovic, D., Cheben, P., Schmid, J. H., Xu, D.-X., Lamontagne, B., Wang, S., … Dado, M. (2015). Subwavelength index engineered surface grating coupler with sub-decibel efficiency for 220-nm silicon-on-insulator waveguides. Optics Express, 23(17), 22628. doi:10.1364/oe.23.022628Zhang, Y., He, Y., Wu, J., Jiang, X., Liu, R., Qiu, C., … Su, Y. (2016). High-extinction-ratio silicon polarization beam splitter with tolerance to waveguide width and coupling length variations. Optics Express, 24(6), 6586. doi:10.1364/oe.24.006586Cantarella, G., Klitis, C., Sorel, M., & Strain, M. J. (2017). Silicon photonic filters with high rejection of both TE and TM modes for on-chip four wave mixing applications. Optics Express, 25(17), 19711. doi:10.1364/oe.25.019711Qiu, H., Jiang, G., Hu, T., Shao, H., Yu, P., Yang, J., & Jiang, X. (2012). FSR-free add–drop filter based on silicon grating-assisted contradirectional couplers. Optics Letters, 38(1), 1. doi:10.1364/ol.38.000001Wang, J., He, S., & Dai, D. (2014). On-chip silicon 8-channel hybrid (de)multiplexer enabling simultaneous mode- and polarization-division-multiplexing. Laser & Photonics Reviews, 8(2), L18-L22. doi:10.1002/lpor.20130015