Apodized Coupled Resonator Optical Waveguides: Theory, design and characterization

In this work we propose the apodization or windowing of the coupling coefficients of the unit cells conforming a coupled resonator device as a mean to reduce the level of secondary sidelobes in the case of SCISSOR configuration [7] or reducing the passband ripples in the case of CROW configuration [8]. This technique is regularly employed in the design of digital filters [18] and has been applied as well in the design of other photonic devices such as corrugated waveguide filters [9] and fiber Bragg gratings [19]. We also propose a novel technique for the apodization of coupled resonator structures by applying a longitudinal offset between resonators in order to modify the power coupling constant, which alleviates the technical requirements required for the production of these devices. We will demonstrate the design, fabrication and characterization of CROW structures employing the apodization through the aforementioned technique.Doménech Gómez, JD. (2013). Apodized Coupled Resonator Optical Waveguides: Theory, design and characterization [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/32278TESI

Silicon Graphene Reconfigurable CROWS and SCISSORS

We propose the incorporation of graphene to integrated coupled resonator waveguides and side-coupled integrated spaced sequence of resonator devices to enable reconfigurable operation. The key element to achieve this is a tunable silicon graphene Mach-Zehnder interferometer (MZI) that acts as an equivalent variable 2 x 2 coupler, where the value of its coupling constant is changed by varying the chemical potential of a graphene section placed on top of one of its arms.Capmany Francoy, J.; Doménech Gómez, JD.; Muñoz, P. (2015). Silicon Graphene Reconfigurable CROWS and SCISSORS. IEEE Photonics Journal. 7(2):1-9. doi:10.1109/JPHOT.2015.2407314S197

Arbitrary Coupling Ratio Multimode Interference Couplers in Silicon-on-Insulator

In this paper, we present the design, manufacturing, characterization, and analysis of the coupling ratio spectral response for multimode interference couplers in silicon-on-insulator (SOI) technology. The couplers were designed using a Si rib waveguide with SiO2 cladding, on a regular 220 nm film and 2 μm buried oxide SOI wafer. A set of eight different designs, three canonical and five using a widened/narrowed coupler body, have been subject of study, with coupling ratios 50:50, 85:15, and 72:28 for the former, and 95:05, 85:15, 75:25, 65:35, and 55:45 for the latter. Two wafers of devices were fabricated, using two different etch depths for the rib waveguides. A set of six dies, three per wafer, whose line metrology matched the design, were retained for characterization. The coupling ratios obtained in the experimental results match, with little deviations, the design targets for a wavelength range between 1525 and 1575 nm, as inferred from spectral measurements and statistical analyses. Excess loss for all the devices is conservatively estimated to be approximately 0.6 dB in average. All the design parameters, body width and length, input/output positions and widths, and tapers dimensions are disclosed for reference.This work was supported by the Spanish CDTI NEOTEC start-up program, the Spanish MICINN project TEC2010-21337, acronym ATOMIC, the Spanish MINECO project TEC2013-42332-P, acronym PIC4ESP, project FEDER UPVOV 10-3E-492, and project FEDER UPVOV 08-3E-008. The work of B. Gargallo was supported by FPI under Grant BES-2011-046100. The work of J.S. Fandino was supported by FPU under grant AP2010-1595.Doménech Gómez, JD.; Sánchez Fandiño, JA.; Gargallo Jaquotot, BA.; Muñoz Muñoz, P. (2014). Arbitrary Coupling Ratio Multimode Interference Couplers in Silicon-on-Insulator. Journal of Lightwave Technology. 32(14):2536-2543. https://doi.org/10.1109/JLT.2014.2329994S25362543321

Low-loss inverted taper edge coupler in silicon nitride

"This paper is a postprint of a paper submitted to and accepted for publication in IET Optoelectronics and is subject to Institution of Engineering and Technology Copyright. The copy of record is available at IET Digital Library"[EN] An inverted lateral taper with one vertical discrete step was designed for a medium confinement silicon nitride waveguide platform in the C-band, as a chip edge coupler, with a predicted insertion loss of 0.58¿dB. The design is supported by an extensive study to evaluate the impact of fabrication process variations on the performance of such a coupler. The device was manufactured and measured, showing an insertion loss of 1.47 dB, which was traced back to fabrication process variations as cross-checked with simulations. To the authors¿ knowledge, the reported edge coupler is the shortest and among the best performing found for silicon nitride platforms.The authors acknowledge financial support through projects TEC2015-69787-REDT PIC4TB, TEC2016-80385-P SINXPECT, TEC2014-54449-C3-1-R, GVA PROMETEO 2017/103, EC H2020-ICT-27-2015 PICs4all CSA 68777.Fernández-Vicente, J.; Baños Lopez, R.; Doménech Gómez, JD.; Domínguez-Horna, C.; Muñoz Muñoz, P. (2019). Low-loss inverted taper edge coupler in silicon nitride. IET Optoelectronics. 13(2):62-66. https://doi.org/10.1049/iet-opt.2018.5065S6266132Marcatili, E. A. J. (1969). Dielectric Rectangular Waveguide and Directional Coupler for Integrated Optics. Bell System Technical Journal, 48(7), 2071-2102. doi:10.1002/j.1538-7305.1969.tb01166.xMiller, S. E. (1969). Integrated Optics: An Introduction. Bell System Technical Journal, 48(7), 2059-2069. doi:10.1002/j.1538-7305.1969.tb01165.xTomlinson, W. J., & Brackett, C. A. (1987). Telecommunications applications of integrated optics and optoelectronics. Proceedings of the IEEE, 75(11), 1512-1523. doi:10.1109/proc.1987.13912Lim, A. E.-J., Junfeng Song, Qing Fang, Chao Li, Xiaoguang Tu, Ning Duan, … Tsung-Yang Liow. (2014). Review of Silicon Photonics Foundry Efforts. IEEE Journal of Selected Topics in Quantum Electronics, 20(4), 405-416. doi:10.1109/jstqe.2013.2293274Smit, M., Leijtens, X., Ambrosius, H., Bente, E., van der Tol, J., Smalbrugge, B., … van Veldhoven, R. (2014). An introduction to InP-based generic integration technology. Semiconductor Science and Technology, 29(8), 083001. doi:10.1088/0268-1242/29/8/083001Taillaert, D., Bogaerts, W., Bienstman, P., Krauss, T. F., Van Daele, P., Moerman, I., … Baets, R. (2002). An out-of-plane grating coupler for efficient butt-coupling between compact planar waveguides and single-mode fibers. IEEE Journal of Quantum Electronics, 38(7), 949-955. doi:10.1109/jqe.2002.1017613Dillon, T., Murakowski, J., Shi, S., & Prather, D. (2008). Fiber-to-waveguide coupler based on the parabolic reflector. Optics Letters, 33(9), 896. doi:10.1364/ol.33.000896Li, H., Cao, Z., Lu, H., & Shen, Q. (2003). Free-space coupling of a light beam into a symmetrical metal-cladding optical waveguide. Applied Physics Letters, 83(14), 2757-2759. doi:10.1063/1.1616205Cardenas, J., Poitras, C. B., Luke, K., Luo, L.-W., Morton, P. A., & Lipson, M. (2014). High Coupling Efficiency Etched Facet Tapers in Silicon Waveguides. IEEE Photonics Technology Letters, 26(23), 2380-2382. doi:10.1109/lpt.2014.2357177Shiraishi, K., Yoda, H., Ohshima, A., Ikedo, H., & Tsai, C. S. (2007). A silicon-based spot-size converter between single-mode fibers and Si-wire waveguides using cascaded tapers. Applied Physics Letters, 91(14), 141120. doi:10.1063/1.2795337Tao, H., Song, J., Fang, Q., Yu, M., Lo, G., & Kwong, D. (2008). Improving coupling efficiency of fiber-waveguide coupling with a double-tip coupler. Optics Express, 16(25), 20803. doi:10.1364/oe.16.020803Muñoz, P., Micó, G., Bru, L., Pastor, D., Pérez, D., Doménech, J., … Domínguez, C. (2017). Silicon Nitride Photonic Integration Platforms for Visible, Near-Infrared and Mid-Infrared Applications. Sensors, 17(9), 2088. doi:10.3390/s17092088Papes, M., Cheben, P., Benedikovic, D., Schmid, J. H., Pond, J., Halir, R., … Vašinek, V. (2016). Fiber-chip edge coupler with large mode size for silicon photonic wire waveguides. Optics Express, 24(5), 5026. doi:10.1364/oe.24.005026Cheben, 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.23.022553Shani, Y., Henry, C. H., Kistler, R. C., Orlowsky, K. J., & Ackerman, D. A. (1989). Efficient coupling of a semiconductor laser to an optical fiber by means of a tapered waveguide on silicon. Applied Physics Letters, 55(23), 2389-2391. doi:10.1063/1.102290Zhuang, L., Marpaung, D., Burla, M., Beeker, W., Leinse, A., & Roeloffzen, C. (2011). Low-loss, high-index-contrast Si_3N_4/SiO_2 optical waveguides for optical delay lines in microwave photonics signal processing. Optics Express, 19(23), 23162. doi:10.1364/oe.19.02316

Electro-refraction modulation predictions for silicon graphene waveguides in the 1540-1560 nm region

(c) 2016 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other users, including reprinting/ republishing this material for advertising or promotional purposes, creating new collective works for resale or redistribution to servers or lists, or reuse of any copyrighted components of this work in other works.We derive analytical approximations for the variation of the effective indices of the fundamental transverse electric (TE) and transverse magnetic (TM) modes with the chemical potential of graphene in three common types of silicon graphene waveguides. In all cases, a third-order polynomial provides an excellent degree of approximation (<; 10-4) over the 1540-1560 nm wavelength band. The approximations can be useful in the design of complex-integrated photonic circuits where graphene is employed to tune the refractive of the dielectric waveguides.This work was supported in part by the Research Excellency Award Program GVA PROMETEO II/2013/012; in part by Spanish MINECO projects TEC2013-42332-P PIF4ESP, TEC2015-69787-REDT PIC4TB, and TEC2014-60378-C2-1-R MEMES; and in part by projects FEDER UPVOV 10-3E-492 and FEDER UPVOV 08-3E-008. The work of D. Perez was supported by the FPI-UPV Grant Program from the Universitat Politecnica de Valencia.Pérez-López, D.; Doménech Gómez, JD.; Muñoz Muñoz, P.; Capmany Francoy, J. (2016). Electro-refraction modulation predictions for silicon graphene waveguides in the 1540-1560 nm region. IEEE Photonics Journal. 8(5):1-13. https://doi.org/10.1109/JPHOT.2016.2598781S1138

Silicon opto-electronic wavelength tracker based on an asymmetric 2x3 Mach-Zehnder Interferometer

[EN] In this paper we report on the experimental demonstration of a Silicon-on-Insulator opto-electronic wavelength tracker for the optical telecommunication C-band. The device consist of a 2x3 Mach-Zehnder Interferometer (MZI) with 10 pm resolution and photo-detectors integrated on the same chip. The MZI is built interconnecting two Multimode Interference (MMI) couplers with two waveguides whose length difference is 56 mm. The first MMI has a coupling ratio of 95:05 to compensate for the propagation loss difference corresponding to the 56 mm. The wavelength tracker design provides three complementary, with 120◦ phase relations, responses. The MZI optical responses exhibit rejection as good as 15 dB, thanks to asymmetric design for the input coupler. Synchronized recorded DC electronic responses for the three photo-detector outputs reproduce the MZI de-phased characteristic, allowing for monitoring wavelength changes with sign.The authors acknowledge financial support by the Spanish CDTI NEOTEC start-up programme, the Spanish MICINN project TEC2010-21337, acronym ATOMIC, the Spanish MINECO project TEC2013-42332-P, acronym PIC4ESP, project FEDER UPVOV 10-3E-492 and project FEDER UPVOV 08-3E-008. B. Gargallo acknowledges financial support through FPI grant BES-2011-046100. J.S. Fandiño acknowledge financial support through FPU grant AP2010-1595.Doménech Gómez, JD.; Sánchez Fandiño, JA.; Gargallo Jaquotot, BA.; Baños López, R.; Muñoz Muñoz, P. (2014). Silicon opto-electronic wavelength tracker based on an asymmetric 2x3 Mach-Zehnder Interferometer. Waves. 6(1):29-34. http://hdl.handle.net/10251/56989S29346

Quantum entropy source on an InP photonic integrated circuit for random number generation

[EN] Random number generators are essential to ensuring performance in information technologies, including cryptography, stochastic simulations, and massive data processing. The quality of random numbers ultimately determines the security and privacy that can be achieved, while the speed at which they can be generated poses limits to the utilization of the available resources. In this work we propose and demonstrate a quantum entropy source for random number generation on an indium phosphide photonic integrated circuit made possible by a new design using two-laser interference and heterodyne detection. The resulting device offers high-speed operation with unprecedented security guarantees and reduced form factor. It is also compatible with complementary metal-oxide semiconductor technology, opening the path to its integration in computation and communication electronic cards, which is particularly relevant for the intensive migration of information processing and storage tasks from local premises to cloud data centers. (C) 2016 Optical Society of AmericaEuropean Regional Development Fund (FEDER) (TEC2013-46168-R); Ministerio de Economia y Competitividad (MINECO) Qu-CARD (SRTC1400C002844XV0); Severo Ochoa (SEV-2015-0522); XPLICA (FIS2014-62181-EXP); European Research Council (ERC) (AQUMET 280169, ERIDIAN 713682); European Union QUIC (641122); Agencia de Gestio d'Ajuts Universitaris i de Recerca (AGAUR) (2014 LLAV 00078, 2014-SGR-1295, 2014-SGR-1623); Fundacion CELLEX.Abellan, C.; Amaya Ocampo, WA.; Doménech Gómez, JD.; Muñoz Muñoz, P.; Capmany Francoy, J.; Longhi, S.; Mitchell, MW.... (2016). Quantum entropy source on an InP photonic integrated circuit for random number generation. Optica. 3(9):989-994. https://doi.org/10.1364/OPTICA.3.000989S98999439Shannon, C. E. (1949). Communication Theory of Secrecy Systems*. Bell System Technical Journal, 28(4), 656-715. doi:10.1002/j.1538-7305.1949.tb00928.xBrin, S., & Page, L. (1998). The anatomy of a large-scale hypertextual Web search engine. Computer Networks and ISDN Systems, 30(1-7), 107-117. doi:10.1016/s0169-7552(98)00110-xMascagni, M., Qiu, Y., & Hin, L.-Y. (2014). High performance computing in quantitative finance: A review from the pseudo-random number generator perspective. Monte Carlo Methods and Applications, 20(2). doi:10.1515/mcma-2013-0020Click, T. H., Liu, A., & Kaminski, G. A. (2010). Quality of random number generators significantly affects results of Monte Carlo simulations for organic and biological systems. Journal of Computational Chemistry, 32(3), 513-524. doi:10.1002/jcc.21638Rarity, J. G., Owens, P. C. M., & Tapster, P. R. (1994). Quantum Random-number Generation and Key Sharing. Journal of Modern Optics, 41(12), 2435-2444. doi:10.1080/09500349414552281Gabriel, C., Wittmann, C., Sych, D., Dong, R., Mauerer, W., Andersen, U. L., … Leuchs, G. (2010). A generator for unique quantum random numbers based on vacuum states. Nature Photonics, 4(10), 711-715. doi:10.1038/nphoton.2010.197Qi, B., Chi, Y.-M., Lo, H.-K., & Qian, L. (2010). High-speed quantum random number generation by measuring phase noise of a single-mode laser. Optics Letters, 35(3), 312. doi:10.1364/ol.35.000312Jofre, M., Curty, M., Steinlechner, F., Anzolin, G., Torres, J. P., Mitchell, M. W., & Pruneri, V. (2011). True random numbers from amplified quantum vacuum. Optics Express, 19(21), 20665. doi:10.1364/oe.19.020665Abellán, C., Amaya, W., Jofre, M., Curty, M., Acín, A., Capmany, J., … Mitchell, M. W. (2014). Ultra-fast quantum randomness generation by accelerated phase diffusion in a pulsed laser diode. Optics Express, 22(2), 1645. doi:10.1364/oe.22.001645Yuan, Z. L., Lucamarini, M., Dynes, J. F., Fröhlich, B., Plews, A., & Shields, A. J. (2014). Robust random number generation using steady-state emission of gain-switched laser diodes. Applied Physics Letters, 104(26), 261112. doi:10.1063/1.4886761Nie, Y.-Q., Huang, L., Liu, Y., Payne, F., Zhang, J., & Pan, J.-W. (2015). The generation of 68 Gbps quantum random number by measuring laser phase fluctuations. Review of Scientific Instruments, 86(6), 063105. doi:10.1063/1.4922417Abellán, C., Amaya, W., Mitrani, D., Pruneri, V., & Mitchell, M. W. (2015). Generation of Fresh and Pure Random Numbers for Loophole-Free Bell Tests. Physical Review Letters, 115(25). doi:10.1103/physrevlett.115.250403Heck, M. J. R., Bauters, J. F., Davenport, M. L., Doylend, J. K., Jain, S., Kurczveil, G., … Bowers, J. E. (2013). Hybrid Silicon Photonic Integrated Circuit Technology. IEEE Journal of Selected Topics in Quantum Electronics, 19(4), 6100117-6100117. doi:10.1109/jstqe.2012.2235413Smit, M., Leijtens, X., Ambrosius, H., Bente, E., van der Tol, J., Smalbrugge, B., … van Veldhoven, R. (2014). An introduction to InP-based generic integration technology. Semiconductor Science and Technology, 29(8), 083001. doi:10.1088/0268-1242/29/8/083001Walmsley, I. A. (2015). Quantum optics: Science and technology in a new light. Science, 348(6234), 525-530. doi:10.1126/science.aab0097Tillmann, M., Dakić, B., Heilmann, R., Nolte, S., Szameit, A., & Walther, P. (2013). Experimental boson sampling. Nature Photonics, 7(7), 540-544. doi:10.1038/nphoton.2013.102Matthews, J. C. F., Politi, A., Stefanov, A., & O’Brien, J. L. (2009). Manipulation of multiphoton entanglement in waveguide quantum circuits. Nature Photonics, 3(6), 346-350. doi:10.1038/nphoton.2009.93Khanmohammadi, A., Enne, R., Hofbauer, M., & Zimmermanna, H. (2015). A Monolithic Silicon Quantum Random Number Generator Based on Measurement of Photon Detection Time. IEEE Photonics Journal, 7(5), 1-13. doi:10.1109/jphot.2015.2479411Zadok, A., Shalom, H., Tur, M., Cornwell, W. D., & Andonovic, I. (1998). Spectral shift and broadening of DFB lasers under direct modulation. IEEE Photonics Technology Letters, 10(12), 1709-1711. doi:10.1109/68.730477Adler, R. (1973). A study of locking phenomena in oscillators. Proceedings of the IEEE, 61(10), 1380-1385. doi:10.1109/proc.1973.9292Aronson, D. G., Doedel, E. J., & Othmer, H. G. (1987). An analytical and numerical study of the bifurcations in a system of linearly-coupled oscillators. Physica D: Nonlinear Phenomena, 25(1-3), 20-104. doi:10.1016/0167-2789(87)90095-9Aronson, D. G., Ermentrout, G. B., & Kopell, N. (1990). Amplitude response of coupled oscillators. Physica D: Nonlinear Phenomena, 41(3), 403-449. doi:10.1016/0167-2789(90)90007-cLang, R., & Kobayashi, K. (1980). 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Application specific photonic integrated circuits through generic integration, a novel paradigm in photonics

[EN] This paper reviews our recent work on integrating photonic devices and sub-systems onto a single photonic chip, by means of generic integration.This work has been partially funded through the Spanish Plan Nacional de I+D+i 2008-2011 project ”Coupled Resonator Optical Waveguide eNgineering (CROWN)” grant no. TEC2008-06145/ TEC, by the Generalitat Valenciana through project PROMETEO/2008/092 and by the EC FP6 contract no. 004525 ePIXnet. J.D. Doménech acknowledges the FPI research grant BES-2009-018381.Muñoz Muñoz, P.; Doménech Gómez, JD.; Artundo Martínez, I.; Habib, C.; Leijtens, X.; De Vries, T.; Robbins, D.... (2011). Application specific photonic integrated circuits through generic integration, a novel paradigm in photonics. Waves. 3:58-64. http://hdl.handle.net/10251/57675S5864

New Mutations in Chronic Lymphocytic Leukemia Identified by Target Enrichment and Deep Sequencing

Chronic lymphocytic leukemia (CLL) is a heterogeneous disease without a well-defined genetic alteration responsible for the onset of the disease. Several lines of evidence coincide in identifying stimulatory and growth signals delivered by B-cell receptor (BCR), and co-receptors together with NFkB pathway, as being the driving force in B-cell survival in CLL. However, the molecular mechanism responsible for this activation has not been identified. Based on the hypothesis that BCR activation may depend on somatic mutations of the BCR and related pathways we have performed a complete mutational screening of 301 selected genes associated with BCR signaling and related pathways using massive parallel sequencing technology in 10 CLL cases. Four mutated genes in coding regions (KRAS, SMARCA2, NFKBIE and PRKD3) have been confirmed by capillary sequencing. In conclusion, this study identifies new genes mutated in CLL, all of them in cases with progressive disease, and demonstrates that next-generation sequencing technologies applied to selected genes or pathways of interest are powerful tools for identifying novel mutational changes