Silicon photonics for telecom and data-com applications

Kiyoshi Asakawa; Yoshimasa Sugimoto; Shigeru Nakamura

doi:10.29026/oea.2020.200011

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Asakawa K, Sugimoto Y, Nakamura S. Silicon photonics for telecom and data-com applications. Opto-Electron Adv 3, 200011 (2020). doi: 10.29026/oea.2020.200011

Citation:

Asakawa K, Sugimoto Y, Nakamura S. Silicon photonics for telecom and data-com applications. Opto-Electron Adv 3, 200011 (2020). doi: 10.29026/oea.2020.200011

OE Historical Open Access

Silicon photonics for telecom and data-com applications

1.
Associate Program, University of Tsukuba, Tsukuba, Ibaraki 305-8571, Japan
2.
Nanotechnology Innovation Station, National Institute for Materials Science (NIMS), 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047, Japan
3.
Biometrics Research Laboratories, NEC Corporation, 1131, Hinode, Abiko, Chiba 270-1198, Japan

More Information

Corresponding author: K. Asakawa, E-mail: asakawae@mtg.biglobe.ne.jp

Received Date 13 April 2020

Accepted Date 17 August 2020

Available Online 28 October 2020

Published Date 23 October 2020

Abstract

Abstract

In recent decades, silicon photonics has attracted much attention in telecom and data-com areas. Constituted of high refractive-index contrast waveguides on silicon-on-insulator (SOI), a variety of integrated photonic passive and active devices have been implemented supported by excellent optical properties of silicon in the mid-infrared spectrum. The main advantage of the silicon photonics is the ability to use complementary metal oxide semiconductor (CMOS) process-compatible fabrication technologies, resulting in high-volume production at low cost. On the other hand, explosively growing traffic in the telecom, data center and high-performance computer demands the data flow to have high speed, wide bandwidth, low cost, and high energy-efficiency, as well as the photonics and electronics to be integrated for ultra-fast data transfer in networks. In practical applications, silicon photonics started with optical interconnect transceivers in the data-com first, and has been now extended to innovative applications such as multi-port optical switches in the telecom network node and integrated optical phased arrays (OPAs) in light detection and ranging (LiDAR). This paper overviews the progresses of silicon photonics from four points reflecting the recent advances mentioned above. CMOS-based silicon photonic platform technologies, applications to optical transceiver in the data-com network, applications to multi-port optical switches in the telecom network and applications to OPA in LiDAR system.
- silicon photonics /
- integration of photonics and electronics /
- CMOS process-compatible fabrication /
- optical interconnect transceiver /
- optical multi-port switch /
- optical phased array

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References

[1]	Asahi Newspaper article (in Japanese), Jan 9, 2017. Google Scholar
[2]	History, NTT Network Innovation Laboratories. https://www.ntt.co.jp/mirai/e/history/. Google Scholar
[3]	Soref R, Bennett B. Electrooptical effects in silicon. IEEE J Quant Electron 23, 123-129 (1987). doi: 10.1109/JQE.1987.1073206 CrossRef Google Scholar
[4]	Gunn G. CMOS Photonics for high-speed interconnects. IEEE Micro 26, 58-66 (2006). Google Scholar
[5]	Jalali B, Fathpour S. Silicon photonics. J Light Wave Technol 24, 4600-4615 (2006). doi: 10.1109/JLT.2006.885782 CrossRef Google Scholar
[6]	Fang Z, Zhao C Z. Recent progress in silicon photonics: a review. ISRN Opt 2012, 428690 (2012). Google Scholar
[7]	Dhiman A. Silicon photonics: a review. IOSR J Appl Phys (IOSR-JAP) 3, 67-79 (2013). doi: 10.9790/4861-0356779 CrossRef Google Scholar
[8]	Kumar A. Silicon photonics: An evolving technology. Int J Eng Sci Res Technol 5, 153-161 (2016). Google Scholar
[9]	Thomson D, Zilkie A, Bowers J E, Komljenovic T, Reed G T et al. Roadmap on silicon photonics. J Opt 18, 073003 (2016). doi: 10.1088/2040-8978/18/7/073003 CrossRef Google Scholar
[10]	Bowers J E, Komljenovic T, Davenport M, Hulme J, Liu A Y et al. Recent advances in silicon photonic integrated circuits. Proc SPIE 9774, 977402 (2017). Google Scholar
[11]	Stojanović V, Ram R J, Popović M, Lin S, Moazeni S et al. Monolithic silicon-photonic platforms in state-of-the-art CMOS SOI processes[Invited]. Opt Express 26, 13106-13121 (2018). doi: 10.1364/OE.26.013106 CrossRef Google Scholar
[12]	Hibino Y. Silica-based planar lightwave circuits and their applications. MRS Bull 28, 365-371 (2003). doi: 10.1557/mrs2003.102 CrossRef Google Scholar
[13]	Bona G L, Germann R, Offrein B J. SiON high-refractive-index waveguide and planar lightwave circuits. IBM J Res Develop 47, 239-249 (2003). doi: 10.1147/rd.472.0239 CrossRef Google Scholar
[14]	Vlasov Y A, McNab S J. Losses in single-mode silicon-on-insulator strip waveguides and bends. Opt Express 12, 1622-1631 (2004). doi: 10.1364/OPEX.12.001622 CrossRef Google Scholar
[15]	Fang A W, Park H, Jones R, Cohen O, Paniccia M J et al. A continuous-wave hybrid AlGaInAs-silicon evanescent laser. IEEE Photon Technol Lett 18, 1143-1145 (2006). doi: 10.1109/LPT.2006.874690 CrossRef Google Scholar
[16]	Pasquariello D, Hjort K. Plasma-assisted InP-to-Si low temperature wafer bonding. IEEE J Sel Top Quant Electron 8, 118-131 (2002). doi: 10.1109/2944.991407 CrossRef Google Scholar
[17]	Lee A, Jiang Q, Tang M C, Seeds A, Liu H Y. Continuous-wave InAs/GaAs quantum-dot laser diodes monolithically grown on Si substrate with low threshold current densities. Opt Express 20, 22181-22187 (2012). doi: 10.1364/OE.20.022181 CrossRef Google Scholar
[18]	Liu A Y, Zhang C, Norman J, Snyder A, Lubyshev D et al. High performance continuous wave 1.3 μm quantum dot lasers on silicon. Appl Phys Lett 104, 041104 (2014). doi: 10.1063/1.4863223 CrossRef Google Scholar
[19]	Park H, Fang A W, Kodama S, Bowers J E. Hybrid silicon evanescent laser fabricated with a silicon waveguide and Ⅲ-V off set quantum wells. Opt Express 13, 9460-9464 (2005). doi: 10.1364/OPEX.13.009460 CrossRef Google Scholar
[20]	Roelkens G, Van Thourhout D, Baets R, Nötzel R, Smit M. Laser emission and photodetection in an InP/InGaAsP layer integrated on and coupled to a silicon-on-insulator waveguide circuit. Opt Express 14, 8154-8159 (2006). doi: 10.1364/OE.14.008154 CrossRef Google Scholar
[21]	Fang A W, Park H, Cohen O, Jones R, Paniccia M J et al.Electrically pumped hybrid AlGaInAs-silicon evanescent laser. Opt Express 14, 9203-9210 (2006). doi: 10.1364/OE.14.009203 CrossRef Google Scholar
[22]	Liang D, Bowers J E. Recent progress in lasers on silicon. Nat Photon 4, 511-517 (2010). doi: 10.1038/nphoton.2010.167 CrossRef Google Scholar
[23]	Maeda M W, Chang-Hasnain C, Von Lehmen A, Izadpanah H, Lin C et al. Multigigabit/s operations of 16-wavelength vertical-cavity surface-emitting laser array. IEEE Photon Technol Lett 3, 863-865 (1991). doi: 10.1109/68.93242 CrossRef Google Scholar
[24]	Chang-Hasnain C J. Tunable VCSEL. IEEE J Sel Top Quantum Electron 6, 978-987 (2000). doi: 10.1109/2944.902146 CrossRef Google Scholar
[25]	Kapon E, Sirbu A. Long-wavelength VCSELs: Power-efficient answer. Nat Photon 3, 27-29 (2009). doi: 10.1038/nphoton.2008.266 CrossRef Google Scholar
[26]	Zhu L, Karagodsky V, Chang-Hasnain C J. Novel high efficiency vertical to in-plane optical coupler. Proc SPIE 8270, 82700L (2012). doi: 10.1117/12.909414 CrossRef Google Scholar
[27]	Ferrara J, Yang W J, Zhu L, Qiao P F, Chang-Hasnain C J. Heterogeneously integrated long-wavelength VCSEL using silicon high contrast grating on an SOI substrate. Opt Express 23, 2512-2523 (2015). doi: 10.1364/OE.23.002512 CrossRef Google Scholar
[28]	Akatsu T, Deguet C, Sanchez L, Allibert F, Rouchon D et al. Germanium-on-insulator (GeOI) substrates-A novel engineered substrate for future high performance devices. Mater Sci Semicond Proc 9, 444-448 (2006). doi: 10.1016/j.mssp.2006.08.077 CrossRef Google Scholar
[29]	Tanoto H, Yoon S F, Lew K L, Loke W K, Dohrman C et al. Electroluminescence and structural characteristics of InAs/In0.1Ga0.9As quantum dots grown on graded Si1-xGex/Si substrate. Appl Phys Lett 95, 141905 (2009). doi: 10.1063/1.3243984 CrossRef Google Scholar
[30]	Liu H Y, Wang T, Jiang Q, Hogg R, Tutu F et al. Long-wavelength InAs/GaAs quantum-dot laser diode monolithically grown on Ge substrate. Nat Photon 5, 416-419 (2011). doi: 10.1038/nphoton.2011.120 CrossRef Google Scholar
[31]	Lee A, Jiang Q, Tang M C, Seeds A, Liu H Y. Continuous-wave InAs/GaAs quantum-dot laser diodes monolithically grown on Si substrate with low threshold current densities. Opt Express 20, 22181-22187 (2012). doi: 10.1364/OE.20.022181 CrossRef Google Scholar
[32]	Seimetz M. Laser linewidth limitations for optical systems with high-order modulation employing feed forward digital carrier phase estimation. In Proceedings of Optical Fiber Communication Conference/National Fiber Optic Engineers Conference OTuM2 (OSA, 2008). Google Scholar
[33]	Komljenovic T, Srinivasan S, Norberg E, Davenport M, Fish G et al. Widely tunable narrow-linewidth monolithically integrated external-cavity semiconductor lasers. IEEE J Sel Top Quant Electron 21, 1501909 (2015). Google Scholar
[34]	Heck M J R, Bauters J F, Davenport, Doylend J K, Jain S et al. Hybird silicon photonic integrated circuit technology. IEEE J Sel Top Quant Electron 19, 6100117 (2013). doi: 10.1109/JSTQE.2012.2235413 CrossRef Google Scholar
[35]	Xia F N, Sekaric L, Vlasov Y. Ultracompact optical buffers on a silicon chip. Nat Photon 1, 65-71 (2007). doi: 10.1038/nphoton.2006.42 CrossRef Google Scholar
[36]	Srinivasan S, Davenport M, Komljenovic T, Hulme J, Spencer D T et al. Coupled-ring-resonator-mirror-based heterogeneous Ⅲ-V silicon tunable laser. IEEE Photon J 7, 2700908 (2015). Google Scholar
[37]	Stanton E J, Heck M J R, Bovington J, Spott A, Bowers J E. Multi-octave spectral beam combiner on ultra-broadband photonic integrated circuit platform. Opt Express 23, 11272-11283 (2015). doi: 10.1364/OE.23.011272 CrossRef Google Scholar
[38]	Yaegashi H. Development of ultra-compact optical transceivers for IoT network utilizing silicon photonics technology. OKI Tech Rev 84, 1-4 (2017). Google Scholar
[39]	Little B E, Chu S T, Pan W, Kokubun Y. Microring resonator arrays for VLSI photonics. IEEE Photon Technol Lett 12, 323-325 (2000). doi: 10.1109/68.826928 CrossRef Google Scholar
[40]	Xu Q F, Fattal D, Beausoleil R G. Silicon microring resonators with 1.5-μm radius. Opt Express 6, 4309-4315 (2008). Google Scholar
[41]	Silicon Photonics and Photonic Integrated Circuits 2020 report. Yole Développement (2020). https://s3.i-micronews.com/uploads/2020/04/YDR20088-Silicon-Photonics-Market-Technology-2020-Sample.pdf Google Scholar
[42]	Merritt R. Globalfoundries Cuts 5% of Workforce (2018-06-11). https://www.eetimes.com/globalfoundries-cuts-5-of-workforce/#. Original source by IC Insights Google Scholar
[43]	Intel labs. The 50G Silicon Photonics Link. http://download.intel.com/pressroom/pdf/photonics/50G_Silicon_Photonics_Link.pdf. Google Scholar
[44]	Soref R A, Lorenzo J P. Single-crystal silicon: a new material for 1.3 and 1.6 μm integrated-optical components. Electron Lett 21, 953-954 (1985). doi: 10.1049/el:19850673 CrossRef Google Scholar
[45]	Reed G T, Headley W R, Png C E J. Silicon photonics: the early years. Proc SPIE 5730, 596921 (2005). Google Scholar
[46]	Rickman A. The commercialization of silicon photonics. Nat Photon 8, 579-582 (2014). doi: 10.1038/nphoton.2014.175 CrossRef Google Scholar
[47]	Liu J F, Cannon D D, Wada K, Ishikawa Y, Jongthammanurak S et al. Tensile strained Ge p-i-n photodetectors on Si platform for C and L band telecommunications. Appl Phys Lett 87, 011110 (2005). doi: 10.1063/1.1993749 CrossRef Google Scholar
[48]	Feng D, Luff B J, Jatar S, Asghari M. Micron-scale silicon photonic devices and circuits. In 2014 Optical Fiber Communications Conference (OFC) TH4C.1 (OSA, 2014); https://doi.org/10.1364/OFC.2014.Th4C.1. Google Scholar
[49]	Boeuf F, Cremer S, Temporiti E, Fere' M, Shaw M et al. Recent progress in silicon photonics R & D and manufacturing on 300mm wafer platform. In 2015 Optical Fiber Communications Conference (OFC) W3A.1 (OSA, 2015); https://doi.org/10.1364/OFC.2015.W3A.1. Google Scholar
[50]	Doerr C, Chen L, Vermeulen D, Nielsen T, Azemati S et al. Single-chip silicon photonics 100-Gb/s coherent transceiver. In 2014 Optical Fiber Communications Conference (OFC) Th5C.1 (OSA, 2014); https://doi.org/10.1364/OFC.2014.Th5C.1. Google Scholar
[51]	Silicon photonics shipments, for datacenter (In units) 2019-2025e. Yole Développement (2020). Google Scholar
[52]	Patterson D, De Sousa I, Achard L M. The future of packaging with silicon photonics. Chip Scale Rev, 1-10 (Jan, 2017). Google Scholar
[53]	Anthony S. IBM demos first fully integrated monolithic silicon photonics chip. Ars Technica UK (May, 2015). https://arstechnica.com/information-technology/2015/05/ibm-demos-first-fully-integrated-monolithic-silicon-photonics-chip/. Google Scholar
[54]	S. Narasimha, K. Onishi, H. M. Nayfeh, A. Waite, M. Weybright et al. High performance 45-nm SOI technology with enhanced strain, porous Low-k BEOL, and immersion lithography. In Proceedings of International Electron Devices Meeting, (IEEE, 2006), 1-4. Google Scholar
[55]	Orcutt J S, Moss B, Sun C, Leu J, Georgas M et al. Open foundry platform for high-performance electronic-photonic integration. Opt Express 20, 12222-12232 (2012). doi: 10.1364/OE.20.012222 CrossRef Google Scholar
[56]	Sun C, Wade M, Georgas M, Lin S, Alloatti L et al. A 45 nm CMOS-SOI Monolithic photonics platform with bit-statistics-based resonant microring thermal tuning. IEEE J Solid-State Circuits 51, 893-907 (2016). doi: 10.1109/JSSC.2016.2519390 CrossRef Google Scholar
[57]	Lee Y, Waterman A, Avizienis R, Cook H, Sun C et al. A 45nm 1.3GHz 16.7 double-precision GFLOPS/W RISC-V processor with vector accelerators. In ESSCIRC 2014-40th European Solid State Circuits Conference (ESSCIRC) 199-202 (IEEE, 2014); http://doi.org/10.1109/ESSCIRC.2014.6942056. Google Scholar
[58]	Akhter M S, Somogyi P, Sun C, Wade M, Meade R et al. Wavelight: a monolithic low latency silicon-photonics communication platform for the next-generation disaggregated cloud data centers. In 2017 IEEE 25th Symposium on High-Performance Interconnects (HOTI) 25-28 (IEEE, 2017); http://doi.org/10.1109/HOTI.2017.23. Google Scholar
[59]	Moazeni S, Lin S, Wade M T, Alloatti L, Ram R J et al. A 40Gb/s PAM-4 transmitter based on a ring-resonator optical DAC in 45nm SOI CMOS. IEEE J Solid-State Circuits 52, 3503-3516 (2017). doi: 10.1109/JSSC.2017.2748620 CrossRef Google Scholar
[60]	Nakamura T, Yashiki K, Mizutani K, Nedachi T, Fujikata J et al. Fingertip-size optical module, "Optical I/O Core", and its application in FPGA. IEICE Trans Electron E102-C, 333-339 (2019). doi: 10.1587/transele.2018ODI0005 CrossRef Google Scholar
[61]	http://www.aiocore.com/technology Google Scholar
[62]	Mogami T, Horikawa T, Kinoshita K, Hagihara Y, Ushida J et al. 1.2 Tbps/cm² enabling silicon photonics IC technology based on 40-nm generation platform. J Lightw Technol 36, 4701-4712 (2018). doi: 10.1109/JLT.2018.2863779 CrossRef Google Scholar
[63]	Uemura T, Ukita A, Takemura K, Kurihara M, Okamoto D et al. 125-μm-pitch×12-channel "Optical Pin" array as I/O structure for novel miniaturized optical transceiver chips. In 2015 IEEE 65th Electronic Components and Technology Conference (ECTC) (IEEE, 2015); http://doi.org/10.1109/ECTC.2015.7159766. Google Scholar
[64]	Yashiki K, Mizutani K, Ushida J, Suzuki Y, Kurihara M et al. 25-Gbps error-free operation of chip-scale Si-photonics optical transmitter over 70℃ with integrated quantum dot laser. In Optical Fiber Communications Conference and Exhibition (OFC) Th1F.7 (OSA, 2016). Google Scholar
[65]	https://www.corning.com/media/worldwide/coc/documents/Fiber/PI1468_07-14_English.pdf. Google Scholar
[66]	Cheng Q X, Bahadori M, Glick M, Rumley S, Bergman K. Recent advances in optical technologies for data centers: a review. Optica 5, 1354-1370 (2018). doi: 10.1364/OPTICA.5.001354 CrossRef Google Scholar
[67]	Hinton H S. An Introduction to Photonic Switching Fabrics (Springer Science & Business Media, New York, 2013). Google Scholar
[68]	Tanizawa K, Suzuki K, Suda S, Matsuura H, Ikeda K et al. Silicon photonic 32×32 strictly-non-blocking blade switch and its full path characterization. In 2016 21st OptoElectronics and Communications Conference (OECC) held jointly with 2016 International Conference on Photonics in Switching (PS) (IEEE, 2016). https://ieeexplore.ieee.org/document/7718222. Google Scholar
[69]	Sakamaki Y, Kawai T, Fukutoku M. Next-generation optical switch technologies for realizing ROADM with more flexible functions. NTT Tech Rev 12, 1-5 (2014). Google Scholar
[70]	Basch E B, Egorov R, Gringeri S, Elby S. Architectural tradeoffs for reconfigurable dense wavelength-division multiplexing systems. IEEE J Sel Top Quant Electron 12, 615-626 (2006). doi: 10.1109/JSTQE.2006.876167 CrossRef Google Scholar
[71]	Gringeri S, Basch B, Shukla V, Egorov R, Xia T J. Flexible architectures for optical transport nodes and networks. IEEE Commun Mag 48, 40-50 (2010). Google Scholar
[72]	https://www.cisco.com/c/dam/m/en_us/network-intelligence/service-provider/digital-transformation/knowledge-network-webinars/pdfs/1213-business-services-ckn.pdf. Google Scholar
[73]	Takeshita H, Hino T, Ishii K, Kurumida J.Prototype highly integrated 8×48 transponder aggregator based on Si photonics for multi-degree colorless, directionless, contentionless reconfigurable optical add/drop multiplexer. IEICE Trans Electron E96-C, 966-973 (2013). doi: 10.1587/transele.E96.C.966 CrossRef Google Scholar
[74]	Yamazaki E, Yamanaka S, Kisaka Y, Nakagawa T, Murata K et al.Fast optical channel recovery in field demonstration of 100-Gbit/s Ethernet over OTN using real-time DSP. Opt Express 19, 13179-13184 (2011). doi: 10.1364/OE.19.013179 CrossRef Google Scholar
[75]	Nakamura S, Yanagimachi S, Takeshita H, Tajima A, Hino T et al.Optical switches based on silicon photonics for ROADM application. IEEE J Sel Top Quant Electron 22, 3600609 (2016). Google Scholar
[76]	Nakamura S, Takahashi S, Ogura I, Ushida J, Kurata K et al.High extinction ratio optical switching independently of temperature with silicon photonic 1×8 switch. In Optical Fiber Communication Conference OTu2I.3 (OSA, 2012); https://doi.org/10.1364/OFC.2012.OTu2I.3. Google Scholar
[77]	Nakamura S, Yanagimachi S, Yanagimachi H, Tajima A, Kato T et al. Compact and low-loss 8×8 silicon photonic switch module for transponder aggregators in CDC-ROADM application. In Optical Fiber Communication Conference M2B.6 (OSA, 2015); https://doi.org/10.1364/OFC.2015.M2B.6. Google Scholar
[78]	Yanagimachi S, Nakamura S, Takeshita H, Tajima A, Kato T et al.8×48 transponder aggregator subsystem using silicon switch modules for flexible photonic network. In Asia Communications and Photonics Conference AF4B.3 (OSA, 2014); https://doi.org/10.1364/ACPC.2014.AF4B.3. Google Scholar
[79]	Cocorullo G, Della Corte F G, Rendina I. Temperature dependence of the thermo-optic coefficient in crystalline silicon between room temperature and[550]at the wavelength of 1523 nm. Appl Phys Lett 74, 3338-3340 (1999). doi: 10.1063/1.123337 CrossRef Google Scholar
[80]	Kurumida J, Ishii K, Takefusa A, Tanimura Y, Yanagimachi S et al. First demonstration of ultra-low-energy hierarchical multi-granular optical path network dynamically controlled through NSI-CS for video related applications. In 2014 the European Conference on Optical Fiber Communications (ECOC 2014) PD.1.3 (IEEE, 2014); http://doi.org/10.1109/ECOC.2014.6964268. Google Scholar
[81]	Nakamura S, Takahashi S, Sakauchi M, Hino T, Yu M et al. Wavelength selective switching with one-chip silicon photonic circuit including 8×8 matrix switch. In Optical Fiber Communication Conference OTuM2 (OSA, 2011). https://doi.org/10.1364/OFC.2011.OTuM2. Google Scholar
[82]	Chen L, Chen Y K. Compact, low-loss and low-power 8×8 broadband silicon optical switch. Opt Express 20, 18977-18985 (2012). doi: 10.1364/OE.20.018977 CrossRef Google Scholar
[83]	Suzuki K, Tanizawa K, Matsukawa T, Cong G W, Kim S H et al. Ultra-compact 8×8 strictly-non-blocking Si-wire PILOSS switch. Opt Express 22, 3887-3894 (2014). doi: 10.1364/OE.22.003887 CrossRef Google Scholar
[84]	Tanizawa K, Suzuki K, Toyama M, Ohtsuka M, Yokoyama N et al. Ultra-compact 32×32 strictly-non-blocking Si-wire optical switch with fan-out LGA interposer. Opt Express 23, 17599-17606 (2015). doi: 10.1364/OE.23.017599 CrossRef Google Scholar
[85]	Goh T, Himeno A, Okuno M, Takahashi H, Hattori K. High-extinction ratio and low-loss silica-based 8×8 strictly nonblocking thermooptic matrix switch. J Lightwave Technol 17, 1192-1199 (1999). doi: 10.1109/50.774253 CrossRef Google Scholar
[86]	Sohma S, Watanabe T, Ooba N, Itoh M, Shibata T et al. Silica-based PLC type 32×32 optical matrix switch. In 2006 European Conference on Optical Communication (ECOC 2006) OThV4 (IEEE, 2006); http://doi.org/10.1109/ECOC.2006.4801113. Google Scholar
[87]	Bahadori M, Gazman A, Janosik N, Rumley S, Zhu Z Y et al. Thermal rectification of integrated microheaters for microring resonators in silicon photonics platform. J Lightwave Technol 36, 773-788 (2017). Google Scholar
[88]	Lu L J, Zhao S Y, Zhou L J, Li D, Li Z X et al. 16×16 non-blocking silicon optical switch based on electro-optic Mach-Zehnder interferometers. Opt Express 24, 9295-9307 (2016). doi: 10.1364/OE.24.009295 CrossRef Google Scholar
[89]	Qiao L, Wang T J, Chu T. 16×16 non-blocking silicon electro-optic switch based on Mach-Zehnder interferometers. In 2016 Optical Fiber Communications Conference and Exhibition (OFC), Anaheim, CA, 1-3 (IEEE, 2016). https://ieeexplore.ieee.org/document/7537295. Google Scholar
[90]	Qiao L, Tang W J, Chu T. 32×32 silicon electro-optic switch with built-in monitors and balanced-status units. Sci Rep 7, 42306 (2017). doi: 10.1038/srep42306 CrossRef Google Scholar
[91]	Huang Y S, Cheng Q X, Bergman K. Automated calibration of balanced control to optimize performance of silicon photonic switch fabrics. In Optical Fiber Communication Conference Th1G.2 (OSA, 2018); http://doi.org/10.1364%2FOFC.2018.Th1G.2. Google Scholar
[92]	Dupuis N, Lee B G, Rylyakov A V, Kuchta D M, Baks C W et al. Design and fabrication of low-insertion-loss and low-crosstalk broadband 2×2 Mach-zehnder silicon photonic switches. J Lightwave Technol 33, 3597-3606 (2015). doi: 10.1109/JLT.2015.2446463 CrossRef Google Scholar
[93]	Dupuis N, Rylyakov A V, Schow C L, Kuchta D M, Baks C W et al. Ultralow crosstalk nanosecond-scale nested 2×2 Mach-Zehnder silicon photonic switch. Opt Lett 41, 3002-3005 (2016). doi: 10.1364/OL.41.003002 CrossRef Google Scholar
[94]	Konoike R, Suzuki K, Inoue T, Matsumoto T, Kurahashi T et al. Lossless operation of SOA-integrated silicon photonics switch for 8×32-Gbaud 16-QAM WDM signals. In Optical Fiber Communication Conference Th4B.6 (OSA, 2018); http://doi.org/10.1364/OFC.2018.Th4B.6. Google Scholar
[95]	Sherwood-Droz N, Wang H, Chen L, Lee B G, Biberman A et al. Optical 4×4 hitless silicon router for optical networks-on-chip (NoC). Opt Express 16, 15915-15922 (2008). doi: 10.1364/OE.16.015915 CrossRef Google Scholar
[96]	Lee B G, Biberman A, Dong P, Lipson M, Bergman K. All-optical comb switch for multiwavelength message routing in silicon photonic networks. IEEE Photonics Technol Lett 20, 767-769 (2008). doi: 10.1109/LPT.2008.921100 CrossRef Google Scholar
[97]	Biberman A, Lira H L R, Padmaraju K, Ophir N, Chan J et al. Broadband silicon photonic electrooptic switch for photonic interconnection networks. IEEE Photonics Technol Lett 23, 504-506 (2011). doi: 10.1109/LPT.2011.2112763 CrossRef Google Scholar
[98]	Khope A S P, Hirokawa T, Netherton A M, Saeidi M, Xia Y et al. On-chip wavelength locking for photonic switches. Opt Lett 42, 4934-4937 (2017). doi: 10.1364/OL.42.004934 CrossRef Google Scholar
[99]	Padmaraju K, Logan D F, Shiraishi T, Ackert J J, Knights A P et al. Wavelength locking and thermally stabilizing microring resonators using dithering signals. J Lightwave Technol 32, 505-512 (2014). doi: 10.1109/JLT.2013.2294564 CrossRef Google Scholar
[100]	Zhu X L, Padmaraju K, Luo L W, Yang S, Glick M et al. Fast wavelength locking of a microring resonator. IEEE Photonics Technol Lett 26, 2365-2368 (2014). doi: 10.1109/LPT.2014.2355720 CrossRef Google Scholar
[101]	DasMahapatra P, Stabile R, Rohit A, Williams K A. Optical crosspoint matrix using broadband resonant switches. IEEE J Sel Top Quant Electron 20, 5900410 (2014). Google Scholar
[102]	Nikolova D, Calhoun D M, Liu Y, Rumley S, Novack A et al. Modular architecture for fully non-blocking silicon photonic switch fabric. Microsyst Nanoeng 3, 16071 (2017). doi: 10.1038/micronano.2016.71 CrossRef Google Scholar
[103]	Marino R M, Davis Jr W R. Jigsaw: a foliage-penetrating 3D imaging laser radar system. Lincoln Lab J 15, 23-36 (2005). Google Scholar
[104]	Doylend J K, Heck M J R, Bovington J T, Peters J D, Davenport M L et al. Hybrid silicon free-space source with integrated beam steering. Proc SPIE 8629, 862911 (2013). doi: 10.1117/12.2004268 CrossRef Google Scholar
[105]	Poulton C V, Yaacobi A, Cole D B, Byrd M J, Raval M et al. Coherent solid-state LIDAR with silicon photonic optical phased arrays. Opt Lett 42, 4091-4094 (2017). doi: 10.1364/OL.42.004091 CrossRef Google Scholar
[106]	McManamon P F, Bos P J, Escuti M K, Heikenfeld J, Serati S et al. A review of phased array steering for narrow-band electrooptical systems. Proc IEEE 97, 1078-1096 (2009). doi: 10.1109/JPROC.2009.2017218 CrossRef Google Scholar
[107]	Schweinsberg A, Shi Z M, Vornehm J E, Boyd R W. A slow-light laser radar system with two-dimensional scanning. Opt Lett 37, 329-331 (2012). doi: 10.1364/OL.37.000329 CrossRef Google Scholar
[108]	Henderson C J, Leyva D G, Wilkinson T D. Free space adaptive optical interconnect at 1.25 Gb/s, with beam steering using a ferroelectric liquid-crystal SLM. J Lightwave Technol 24, 1989-1997 (2006). doi: 10.1109/JLT.2006.871015 CrossRef Google Scholar
[109]	Doylend J K, Heck M J R, Bovington J T, Peters J D, Coldren L A et al. Two-dimensional free-space beam steering with an optical phased array on silicon-on-insulator. Opt Express 19, 21595-21604 (2011). doi: 10.1364/OE.19.021595 CrossRef Google Scholar
[110]	Hulme J C, Doylend J K, Heck M J R, Peters J D, Davenport M L et al. Fully integrated hybrid silicon two dimensional beam scanner. Opt Express 23, 5861-5874 (2015). doi: 10.1364/OE.23.005861 CrossRef Google Scholar
[111]	Levinson J, Askeland J, Becker J, Dolson J, Held D et al. Towards fully autonomous driving: Systems and algorithms. In 2011 IEEE Intelligent Vehicles Symposium (IV) 163-168 (IEEE, 2011); http://doi.org/10.1109/IVS.2011.5940562. Google Scholar
[112]	Lalonde J F, Vandapel N, Huber D F, Hebert M. Natural terrain classification using three-dimensional ladar data for ground robot mobility. J Field Robot 23, 839-861 (2006). doi: 10.1002/rob.20134 CrossRef Google Scholar
[113]	Lin Y J, Hyyppä J, Jaakkola A. Mini-UAV-borne LIDAR for fine-scale mapping. IEEE Geosci Remote Sens Lett 8, 426-430 (2011). doi: 10.1109/LGRS.2010.2079913 CrossRef Google Scholar
[114]	Schween J H, Hirsikko A, Löhnert U, Crewell S. Mixing-layer height retrieval with ceilometer and Doppler lidar: from case studies to long-term assessment. Atmos Meas Tech 7, 3685-3704 (2014). doi: 10.5194/amt-7-3685-2014 CrossRef Google Scholar
[115]	Davis S R, Rommel S D, Gann D, Luey B, Gamble J D et al. A lightweight, rugged, solid state laser radar system enabled by non-mechanical electro-optic beam steerers. Proc SPIE 9832, 98320K (2016). Google Scholar
[116]	Pierrottet D, Amzajerdian F, Petway L, Barnes B, Lockard G et al. Linear FMCW Laser Radar for Precision Range and Vector Velocity Measurements. In Proceedings of the Materials Research Society Symposium, San Francisco, CA, USA, 1076 (2008); http://doi.org/10.1557/PROC-1076-K04-06. Google Scholar
[117]	Poulton C V, Yaacobi A, Cole D B, Byrd M J, Raval M et al. Large-scale silicon nitride nanophotonic phased arrays at infrared and visible wavelengths. Opt Lett 42, 21-24 (2017). doi: 10.1364/OL.42.000021 CrossRef Google Scholar
[118]	Iovanna P, Cavaliere F, Testa F, Stracca S, Botarri G et al. Future proof optical network infrastructure for 5G transport. J Opt Commun Netw 8, B80-B92 (2016). Google Scholar
[119]	Shen Y C, Harris N C, Skirlo S, Prabhu M, Jones T B et al. Deep learning with coherent nanophotonic circuits. Nat Photon 11, 441-446 (2017). doi: 10.1038/nphoton.2017.93 CrossRef Google Scholar
[120]	Peng H T, Nahmias M A, de Lima T F, Tait A N, Shastri B J. Neuromorphic photonic integrated circuits. IEEE J Sel Top Quant Electron 24, 6101715 (2018). Google Scholar
[121]	Cheben P, Halir R, Schmid J H, Atwater H A, Smith D R. Subwavelength integrated photonics. Nature 560, 565-572 (2018) doi: 10.1038/s41586-018-0421-7 CrossRef Google Scholar