Large-scale optical switches by thermo-optic waveguide lens

Laboratory of Photonic Integration, School of Engineering, Westlake University, 18 Shilongshan Road, Hangzhou, China

Funds: The authors would like to thank the industry partners for their sincere support and many valuable discussions.

摘要

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Abstract:
Optical switches are desired in telecom and datacom as an upgrade to electrical ones for lower power consumption and expenses while improving bandwidth and network transparency. Compact, integrated optical switches are attractive thanks to their scalability, readiness for mass production, and robustness against mechanical disturbances. The basic unit relies mostly on a microring resonator or a Mach–Zehnder interferometer for binary “bar” and “cross” switching. Such single-mode structures are often wavelength / polarization dependent, sensitive to phase errors and loss-prone. Furthermore, when they are cascaded to a network, the number of control units grows quickly with the port count, causing high complexity in electronic wiring and drive circuit integration. Herein, we propose a new switching method by thermo-optic waveguide lens. Essentially, this multimode waveguide forms a square law medium by a pair of heater electrodes and focuses light within a chip by robust 1 × 1 imaging. A 1 × 24 basic switch is demonstrated with 32 electrodes and only two are biased at a time for a chosen output. By two-level cascading, the switch expands to 576 ports and only four electrodes are needed for one path. The chips are fabricated on wafer scale in a low-budget laboratory without resorting to foundries. Yet, the performance goes beyond state of the art for low insertion loss, low wavelength dependence and low polarization dependence. This work provides an original, alternative, and practical route to construct large-scale optical switches, enabling broad applications in telecom, datacom and photonic computing.

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参考文献(32)

[1]	Cheng Q, Rumley S, Bahadori M, Bergman K. Photonic switching in high performance datacenters. Opt Express. 2018;26(12):16022–43.
[2]	Wu B, Zhang W, Zhou H, Dong J, Huang D, Wai PKA, et al. Chip-to-chip optical multimode communication with universal mode processors. PhotoniX. 2023;4(37):1–14.
[3]	Zhou H, Dong J, Cheng J, Dong W, Huang C, Shen Y, et al. Photonic matrix multiplication lights up photonic accelerator and beyond. Light Sci Appl. 2022;11(1):30.
[4]	De Dobbelaere P, Falta K, Gloeckner S, Patra S. Digital MEMS for optical switching. IEEE Commun Mag. 2002;40(3):88–95.
[5]	Mizukami M, Yamaguchi J, Nemoto N, Kawajiri Y, Hirata H, Uchiyama S, et al. 128×128 three-dimensional MEMS optical switch module with simultaneous optical path connection for optical cross-connect systems. Appl Opt. 2011;50(21):4037–41.
[6]	Cao T, Hu T, Zhao Y. Research status and development trend of MEMS switches: a review. Micromachines. 2020;11(7):694.
[7]	Wang Z, Xu J, Yang P, Wang Z, Duong LHK, Chen X. High-radix nonblocking integrated optical switching fabric for data center. J Lightwave Technol. 2017;35(19):4268–81.
[8]	Wang C, Zhang D, Yue J, Lin H, Zhang X, Zhang T, et al. On-chip optical sources of 3D photonic integration based on active fluorescent polymer waveguide microdisks for light display application. PhotoniX. 2023;4(13):1–15.
[9]	Wang F, Wang X, Zhou H, Zhou Q, Hao Y, Jiang X, et al. Fano-resonance-based Mach-Zehnder optical switch employing dual-bus coupled ring resonator as two-beam interferometer. Opt Express. 2009;17(9):7708–16.
[10]	Cheng Q, Dai LY, Abrams NC, Hung Y-H, Morrissey PE, Glick M, et al. Ultralow-crosstalk, strictly non-blocking microring-based optical switch. Photonics Res. 2019;7(2):155–61.
[11]	Watts MR, Sun J, DeRose C, Trotter DC, Young RW, Nielson GN. Adiabatic thermo-optic Mach-Zehnder switch. Opt Lett. 2013;38(5):733–5.
[12]	Kita T, Mendez-Astudillo M. Ultrafast silicon MZI optical switch with periodic electrodes and integrated heat sink. J Lightwave Technol. 2021;39(15):5054–60.
[13]	Jayatilleka H, Murray K, Guillén-Torres MÁ, Caverley M, Hu R, Jaeger NA, et al. Wavelength tuning and stabilization of microring-based filters using silicon in-resonator photoconductive heaters. Opt Express. 2015;23(19):25084–97.
[14]	Lu L, Zhao S, Zhou L, Li D, Li Z, Wang M, et al. 16×16 non-blocking silicon optical switch based on electro-optic Mach-Zehnder interferometers. Opt Express. 2016;24(9):9295–307.
[15]	Qiao L, Tang W, Chu T. 32×32 silicon electro-optic switch with built-in monitors and balanced-status units. Sci Rep. 2017;7(1):42306.
[16]	Dumais P, Goodwill DJ, Celo D, Jiang J, Zhang C, Zhao F, et al. Silicon photonic switch subsystem with 900 monolithically integrated calibration photodiodes and 64-fiber package. J Lightwave Technol. 2018;36(2):233–8.
[17]	Suzuki K, Konoike R, Hasegawa J, Suda S, Matsuura H, Ikeda K, et al. Low-insertion-loss and power-efficient 32×32 silicon photonics switch with extremely high-Δ silica PLC connector. J Lightwave Technol. 2019;37(1):116–22.
[18]	Suzuki K, Konoike R, Yokoyama N, Seki M, Ohtsuka M, Saitoh S, et al. Nonduplicate polarization-diversity 32×32 silicon photonics switch based on a SiN/Si double-layer platform. J Lightwave Technol. 2020;38(2):226–32.
[19]	Watanabe T, Goh T, Okuno M, Sohma Si, Shibata T, Itoh M, et al., editors. Silica-based PLC 1×128 thermo-optic switch. Proceedings 27th European Conference on Optical Communication (Cat No 01TH8551). Amsterdam: IEEE; 2001. p. 134–5.
[20]	Gao W, Li X, Lu L, Liu C, Chen J, Zhou L. Broadband 32×32 strictly-nonblocking optical switch on a multi-layer Si₃N₄-on-SOI platform. Laser Photonics Rev. 2023;17(11):2300275.
[21]	Suzuki K, Konoike R, Matsuura H, Matsumoto R, Inoue T, Namiki S, et al., editors. Recent advances in large-scale optical switches based on silicon photonics. Optical Fiber Communication Conference. San Diego: Optica Publishing Group; 2022. p. W4B. 6.
[22]	Milanizadeh M, Aguiar D, Melloni A, Morichetti F. Canceling thermal cross-talk effects in photonic integrated circuits. J Lightwave Technol. 2019;37(4):1325–32.
[23]	Huang Y, Cheng Q, Hung Y-H, Guan H, Meng X, Novack A, et al. Multi-stage 8×8 silicon photonic switch based on dual-microring switching elements. J Lightwave Technol. 2019;38(2):194–201.
[24]	Marcuse D. Light propagation in square law medium. In: Light transmission optics 2nd. New York: Van Nostrand Reinhold. 1982. p. 263–285.
[25]	Gomez-Reino C, Perez MV, Bao C, Flores-Arias MT. Design of GRIN optical components for coupling and interconnects. Laser Photonics Rev. 2008;2(3):203–15.
[26]	Niu Y, Niu Y, Hu X, Hu Y, Du Q, Yu S, et al. On-chip wavefront shaping in spacing-varied waveguide arrays. Nanophotonics. 2023;12(19):3737–45.
[27]	Dang Z, Deng Z, Chen T, Ding Z, Zhang Z. C/L-band 2-port broadband wavelength multiplexing switch using polymer waveguides. J Lightwave Technol. 2023;41(8):2451–7.
[28]	Deng Z, Ding Z, Chen T, Zhang Z. Thermal gradient driven variable optical attenuator with on-chip CNT absorber. IEEE Photonics Technol Lett. 2024;36(4):243–6.
[29]	Chen T, Dang Z, Ding Z, Liu Z, Zhang Z. Multibit NOT logic gate enabled by a function programmable optical waveguide. Opt Lett. 2022;47(14):3519–22.
[30]	Soldano LB, Pennings EC. Optical multi-mode interference devices based on self-imaging: principles and applications. J Lightwave Technol. 1995;13(4):615–27.
[31]	Zhang Z, Maese-Novo A, Polatynski A, Mueller T, Irmscher G, de Felipe D, et al., editors. Colorless, dual-polarization 90 hybrid with integrated VOAs and local oscillator on polymer platform. Optical Fiber Communication Conference. Los Angeles: Optica Publishing Group; 2015. p. Th1F. 3.
[32]	Soganci IM, Tanemura T, Nakano Y. Integrated phased-array switches for large-scale photonic routing on chip. Laser Photonics Rev. 2012;6(4):549–63.