T. Watanabe, D. Ishio, T. Nagayama, and S. Fukushima, "3-stage Mach-Zehnder interferometer optical switch with ripple-free response," 30th Microoptics Conference (MOC 2025), Utsunomiya, paper PO-46, Technical Digest pp. 136-137, October 2025.
T. Watanabe, H. Nakamura, T. Nagayama, and S. Fukushima, "Perfect crossbar optical switch with imperfect couplers," 30th Optoelectronics and Communications Conference / International Conference on Photonics in Switching and Computing (OECC/PSC 2025), Sapporo, paper TuP-E-10, July 2025.
T. Watanabe, S. Taguchi, T. Nagayama, and S. Fukushima, "Rising time reduction by cascading Mach-Zehnder interferometer optical switches," 29th Microoptics Conference (MOC 2024), Kaohsiung, Taiwan, paper PO-97, October 2024.
T. Kiritoshi, T. Watanabe, T. Nagayama, and S. Fukushima, "Coupling characteristics of a mode multi/demultiplexer with a vertically stacked asymmetric directional coupler," 27th Optoelectronics and Communications Conference / International Conference on Photonics in Switching and Computing (OECC/PSC 2022), Toyama (hybrid), paper TuP-E-3, July 2022.
M. Kawasako, T. Watanabe, T. Nagayama, and S. Fukushima, "4-stage Mach-Zehnder interferometer optical switch with phase generating couplers," 26th Microoptics Conference (MOC 2021), Hamamatsu (online), paper PO-40, Technical Digest pp. 222-223, September 2021.
K. Sainohira, T. Watanabe, T. Nagayama, and S. Fukushima, "Truncated spot size converters for silicon photonic wire waveguides," 26th Optoelectronics and Communications Conference (OECC 2021), Hong Kong (online), paper W4F.3, July 2021.
T. Watanabe, K. Tasaki, T. Nagayama, and S. Fukushima, "Nested Mach-Zehnder interferometer optical switch with low crosstalk," 24th Microoptics Conference (MOC 2019), Toyama, paper P-69, Technical Digest pp. 234-235, November 2019.
W. Yamauchi, T. Watanabe, T. Nagayama, and S. Fukushima, "Joint-switching architecture utilizing waveguide-based multicast switch in CDC-ROADM for multi-core fiber networks," 24th Optoelectronics and Communications Conference / International Conference on Photonics in Switching and Computing (OECC/PSC 2019), Fukuoka, paper WP4-F4, July 2019.
S. Shimada, T. Watanabe, T. Nagayama, and S. Fukushima, "Design of arrayed-waveguide optical switch employing window function," 23rd Microoptics Conference (MOC 2018), Taipei, paper P-49, October 2018.
K. Ueda, Y. Mori, H. Hasegawa, K. Sato, and T. Watanabe, "Large-scale and simple-configuration optical switch enabled by asymmetric-port-count sub-switches," 2016 IEEE Photonics Conference (IPC 2016), Hawaii, paper ThG1.2, invited, October 2016.
K. Ueda, Y. Mori, H. Hasegawa, H. Matsuura, K. Ishii, H. Kuwatsuka, S. Namiki, T. Watanabe, and K. Sato, "Demonstration of 1,440×1,440 fast optical circuit switch for datacenter networking," 21st Optoelectronics and Communications Conference / International Conference on Photonics in Switching (OECC/PS 2016), Niigata, paper WF1-3, July 2016.
N. Nemoto, Y. Ikuma, K. Suzuki, O. Moriwaki, T. Watanabe, M. Itoh, and T. Takahashi, "8×8 wavelength cross connect with add/drop ports integrated in spatial and planar optical circuit," 41st European Conference on Optical Communication (ECOC 2015), Valencia, Spain, paper Tu.3.5.1, September 2015.
K. Ueda, Y. Mori, H. Hasegawa, K. Sato, and T. Watanabe, "Large-scale optical switch with simplified sub-switch connections for datacenter application," Photonics in Switching Conference (PS 2015), Florence, Italy, paper FrIII2.2, Proceedings pp. 366-368, September 2015.
S. Takashina, H. Ishida, Y. Mori, H. Hasegawa, K. Sato, and T. Watanabe, "Demonstration of large-port-count and compact ROADM that exhibits virtual-C/D/C performance," Optical Fiber Communication Conference (OFC 2015), Los Angeles, California, paper W3J.6, March 2015.
K. Ueda, Y. Mori, H. Hasegawa, K. Sato, and T. Watanabe, "Large-scale optical-switch prototype compactly implemented with novel functional configuration," Optical Fiber Communication Conference (OFC 2015), Los Angeles, California, paper W3D.1, March 2015.
M. Niwa, S. Takashina, Y. Mori, H. Hasegawa, K. Sato, and T. Watanabe, "Wavelength-tunable filter utilizing non-cyclic arrayed waveguide grating to create colorless/directionless/contentionless ROADMs," Photonics West 2015, OPTO, San Francisco, California, paper 9388-07, Proceedings of SPIE, vol. 9388, 9388-07, February 2015.
S. Takashina, Y. Mori, H. Hasegawa, K. Sato, and T. Watanabe, "Low-loss and low-power-consumption wavelength tunable filter enabling colorless/directionless/contentionless optical drop in ROADMs," 40th European Conference on Optical Communication (ECOC 2014), Cannes, France, paper We.3.5.2, September 2014.
K. Ueda, Y. Mori, H. Hasegawa, K. Sato, and T. Watanabe, "Novel large-port-count optical-switch architecture for optical interconnection in datacenter," 40th European Conference on Optical Communication (ECOC 2014), Cannes, France, paper We.3.5.1, September 2014.
S. Takashina, Y. Mori, H. Hasegawa, K. Sato, and T. Watanabe, "Low crosstalk wavelength tunable filter that utilizes symmetric and asymmetric Mach-Zehnder interferometers," Optical Fiber Communication Conference (OFC 2014), San Francisco, California, paper Th3F.6, March 2014.
K. Takaha, Y. Mori, H. Hasegawa, K. Sato, and T. Watanabe, "A 204.8 Tbps throughput 64×64 optical cross-connect prototype that allows C/D/C add/drop," Optical Fiber Communication Conference (OFC 2014), San Francisco, California, paper M2K.1, March 2014.
T. Watanabe, T. Mizuno, Y. Hashizume, and T. Takahashi, "Silica-based PLC 1×N switch for all wavelength bands," Optical Fiber Communication Conference (OFC 2014), San Francisco, California, paper Th1I.5, March 2014.
T. Watanabe, S. Sohma, and S. Kamei, "Colorless optical add/drop using small matrix switch and cyclic AWG," 18th Microoptics Conference (MOC 2013), Tokyo, paper F-1, Technical Digest p. 40, October 2013.
S. Shimazaki, Y. Tamura, D. Hanawa, K. Oguchi, T. Watanabe, and T. Takahashi, "Cost comparison of different ROADM architectures," 19th Asia-Pacific Conference on Communications (APCC 2013), Bali, Indonesia, Proceedings pp. 501-504, August 2013.
H. Ono, T. Watanabe, K. Suzuki, A. Mori, T. Takahashi, and T. Sakamoto, "Power consumption analysis of PLC-based optical switches and variable attenuators for variable gain optical fiber amplifier," 18th Optoelectronics and Communications Conference / International Conference on Photonics in Switching (OECC/PS 2013), Kyoto, paper ThL3-4, June 2013.
T. Niwa, H. Hasegawa, K. Sato, T. Watanabe, H. Takahashi, and S. Sohma, "Compact integrated tunable filter utilizing AWG routing function and small switches," Optical Fiber Communication Conference / National Fiber Optic Engineers Conference (OFC/NFOEC 2013), Anaheim, California, paper OW1C.2, March 2013.
T. Niwa, H. Hasegawa, K. Sato, T. Watanabe, and H. Takahashi, "A novel large-scale wavelength routing switch configuration exploiting small-size arrayed waveguide gratings," Asia Communications and Photonics Conference (ACP 2012), Guangzhou, China, paper ATh2C.4, November 2012.
T. Ban, H. Hasegawa, K. Sato, T. Watanabe, and H. Takahashi, "A novel large-scale OXC architecture that employs wavelength path switching and fiber selection," 38th European Conference on Optical Communication (ECOC 2012), Amsterdam, paper We.3.D.1, September 2012.
K. Seno, K. Suzuki, N. Ooba, T. Watanabe, M. Itoh, T. Sakamoto, and T. Takahashi, "Spatial beam transformer for wavelength selective switch consisting of silica-based planar lightwave circuit," Optical Fiber Communication Conference / National Fiber Optic Engineers Conference (OFC/NFOEC 2012), Los Angeles, California, paper JTh2A.5, March 2012.
T. Niwa, R. Hirako, H. Hasegawa, K. Sato, M. Okuno, and T. Watanabe, "Compact wavelength tunable filter fabricated on a PLC chip that construct colorless/directionless/contentionless drop function in optical cross-connect," Optical Fiber Communication Conference / National Fiber Optic Engineers Conference (OFC/NFOEC 2012), Los Angeles, California, paper OTh3D.6, March 2012.
T. Watanabe, K. Suzuki, and T. Takahashi, "Silica-based PLC transponder aggregators for colorless, directionless, and contentionless ROADM," Optical Fiber Communication Conference / National Fiber Optic Engineers Conference (OFC/NFOEC 2012), Los Angeles, California, paper OTh3D.1, invited, March 2012.
T. Watanabe, Y. Hashizume, and H. Takahashi, "Double-branched 1×29 silica-based PLC switch with low loss and low power consumption," 17th Microoptics Conference (MOC 2011), Sendai, paper J-2, November 2011.
Y. Sakamaki, T. Kawai, T. Komukai, M. Fukutoku, T. Kataoka, T. Watanabe, and Y. Ishii, "Experimental demonstration of colourless, directionless, contentionless ROADM using 1×43 WSS and PLC-based transponder aggregator for 127-Gbit/s DP-QPSK system," 37th European Conference on Optical Communication (ECOC 2011), Geneva, Switzerland, paper Th.12.A.3, September 2011.
H. Ono, T. Watanabe, K. Suzuki, A. Mori, T. Takahashi, and T. Sakamoto, "An erbium-doped fibre amplifier with widely variable gain employing integrated components on a planar lightwave circuit," 37th European Conference on Optical Communication (ECOC 2011), Geneva, Switzerland, paper Th.11.LeCervin.6, September 2011.
T. Tanaka, N. Ooba, M. Ishii, K. Seno, T. Watanabe, H. Ono, K. Suzuki, T. Sakamoto, and T. Takahashi, "Temperature independent and reduced group delay ripple operation of multi-channel tunable optical dispersion compensator," 16th Optoelectronics and Communications Conference (OECC 2011), Kaohsiung, Taiwan, paper 7E2_4, Technical Digest pp. 504-505, July 2011.
K. Seno, N. Ooba, K. Suzuki, T. Watanabe, M. Itoh, and T. Sakamoto, "Wide-passband 88-wavelength channel-by-channel tunable optical dispersion compensator with 50-GHz spacing," Optical Fiber Communication Conference / National Fiber Optic Engineers Conference (OFC/NFOEC 2011), Los Angeles, California, paper OWM5, March 2011.
T. Watanabe, K. Suzuki, T. Goh, K. Hattori, A. Mori, T. Takahashi, T. Sakamoto, K. Morita, S. Sohma, and S. Kamei, "Compact PLC-based transponder aggregator for colorless and directionless ROADM," Optical Fiber Communication Conference / National Fiber Optic Engineers Conference (OFC/NFOEC 2011), Los Angeles, California, paper OTuD3, March 2011.
T. Kawai, T. Kobayashi, T. Inui, T. Komukai, T. Kataoka, M. Fukutoku, M. Tomizawa, Y. Ishii, E. Hashimoto, Y. Kawajiri, and T. Watanabe, "Multi-degree ROADM based on massive port count WSS with integrated colorless ports," Optical Fiber Communication Conference / National Fiber Optic Engineers Conference (OFC/NFOEC 2011), Los Angeles, California, paper OTuD2, March 2011.
K. Seno, K. Suzuki, N. Ooba, T. Watanabe, M. Itoh, S. Mino, and T. Sakamoto, "50-wavelength channel-by-channel tunable optical dispersion compensator using combination of arrayed-waveguide and bulk gratings," Optical Fiber Communication Conference / National Fiber Optic Engineers Conference (OFC/NFOEC 2010), San Diego, California, paper OMT7, March 2010.
M. Okada, J. Kani, T. Watanabe, and N. Yoshimoto, "An optimal investment strategy of optical transceivers for static WDM networks," Optical Fiber Communication Conference / National Fiber Optic Engineers Conference (OFC/NFOEC 2008), Anaheim, California, paper NTuD3, February 2008.
S. Sohma, T. Watanabe, N. Ooba, M. Itoh, T. Shibata, and H. Takahashi, "Silica-based PLC type 32×32 optical matrix switch," 32nd European Conference on Optical Communication (ECOC 2006), Cannes, France, paper Tu4.4.3, Proceedings vol. 2, pp. 145-146, September 2006.
T. Watanabe, T. Imai, and N. Yoshimoto, "Compact wavelength division multi/demultiplexers with hole-assisted fiber pigtails," 12th Microoptics Conference (MOC 2006), Seoul, paper D-4, Technical Digest pp. 80-81, September 2006.
T. Watanabe, S. Sohma, T. Goh, T. Shibata, and H. Takahashi, "Compact 8×8 silica-based PLC switch with compressed arrangement," 31st European Conference on Optical Communication (ECOC 2005), Glasgow, Scotland, paper Th3.6.3, Proceedings vol. 4, pp. 991-992, September 2005.
S. Sohma, T. Watanabe, T. Shibata, and H. Takahashi, "Compact and low power consumption 16×16 optical matrix switch with silica-based PLC technology," Optical Fiber Communication Conference / National Fiber Optic Engineers Conference (OFC/NFOEC 2005), Anaheim, California, paper OThV4, March 2005.
S. Sohma, S. Mino, T. Watanabe, M. Ishii, T. Shibata, and H. Takahashi, "Solid-state optical switches using planar lightwave circuit and IC-on-PLC technologies," Asia-Pacific Optical Communications Conference (APOC 2004), Beijing, China, paper 5625-117, Proceedings of SPIE, vol. 5625, pp. 767-775, November 2004.
T. Watanabe, "Silica-based PLC optical switches designed and fabricated for OADM and OXC," 9th Optoelectronics and Communications Conference / 3rd Conference on Optical Internet (OECC/COIN 2004), Yokohama, paper 13F2-3, invited, Technical Digest pp. 110-111, July 2004.
Y. Hashizume, H. Takahashi, T. Watanabe, S. Sohma, T. Shibata, and M. Okuno, "Compact 32-channel 2×2 optical switch array based on PLC technology for OADM systems," 29th European Conference on Optical Communication / 14th International Conference on Integrated Optic and Optical Fibre Communications (ECOC/IOOC 2003), Rimini, Italy, paper Mo3.5.4, September 2003.
T. Goh, H. Takahashi, T. Watanabe, M. Kobayashi, T. Shibata, M. Ishii, S. Sohma, Y. Abe, M. Okuno, and Y. Hibino, "Scalable 128×128 optical switch system composed of planar lightwave circuit and fiber sheet for optical crossconnect," 28th European Conference on Optical Communication (ECOC 2002), Copenhagen, paper 6.2.7, September 2002.
H. Takahashi, T. Goh, T. Shibata, M. Okuno, Y. Hibino, and T. Watanabe, "High performance 8-arrayed 1×8 optical switch based on planar lightwave circuit for photonic networks," 28th European Conference on Optical Communication (ECOC 2002), Copenhagen, paper 4.2.6, September 2002.
T. Watanabe, T. Goh, M. Okuno, S. Sohma, T. Shibata, M. Itoh, M. Kobayashi, M. Ishii, A. Sugita, and Y. Hibino, "Silica-based PLC 1×128 thermo-optic switch," 27th European Conference on Optical Communication (ECOC 2001), Amsterdam, paper Tu.L.1.2, Proceedings vol. 2, pp. 134-135, September 2001.
M. Okuno, T. Watanabe, T. Goh, T. Kominato, T. Shibata, T. Kawai, M. Koga, and Y. Hibino, "Low-loss and high extinction ratio silica-based 1×N thermo-optic switches," 6th Optoelectronics and Communications Conference / 13th International Conference on Integrated Optic and Optical Fibre Communications (OECC/IOOC 2001), Sydney, paper MD.5, Technical Digest pp. 39-41, July 2001.
T. Watanabe, F. Kano, S. Kuwano, H. Suzuki, and M. Koga, "Scale expansion of transparent photonic transport network based on distributed Raman amplification," 25th European Conference on Optical Communication (ECOC 1999), Nice, France, paper ThA1.4, Proceedings vol. 2, pp. 212-213, September 1999.
H. Yasaka, T. Kawai, M. Teshima, T. Watanabe, N. Sakaida, and M. Koga, "VWP photonic transport systems with opto-electronic wavelength conversion," IEEE Lasers and Electro-Optics Society 1998 Annual Meeting (LEOS 1998), Orlando, Florida, paper WZ1, invited, Proceedings vol. 1, pp. 352-353, December 1998.
T. Watanabe, H. Yasaka, N. Sakaida, and M. Koga, "Using Mach-Zehnder frequency discriminator to suppress waveform distortion of chirp-controlled signal by semiconductor optical amplifier," Optical Amplifiers and their Applications Topical Meeting (OAA 1998), Vail, Colorado, paper TuA3, OSA Technical Digest pp. 72-75, July 1998.
T. Watanabe, N. Sakaida, H. Yasaka, and M. Koga, "Chirp control of optical signal using semiconductor optical amplifier," 3rd Optoelectronics and Communications Conference (OECC 1998), Makuhari, paper 14A1-2, Technical Digest pp. 86-87, July 1998.
S. Toyoda, T. Watanabe, N. Ooba, T. Kurihara, and S. Imamura, "Design of cross-linked silicone for thermo-optic devices," International Symposium on Image Processing Molecular Systems (IPMS 1998), Tsukuba, Extended Abstracts p. 60, March 1998.
T. Watanabe, N. Ooba, Y. Hida, S. Hayashida, T. Kurihara, and S. Imamura, "Digital thermo-optic switch formed using silicone resin," 8th European Conference on Integrated Optics (ECIO 1997) / OSA Topical Meeting on Photonics in Switching (PS 1997), Stockholm, paper JFA4, Technical Digest ECIO, pp. 474-477, and OSA Technical Digest vol. 10, pp. 162-165, April 1997.
M. Usui, M. Hikita, T. Watanabe, M. Amano, S. Sugawara, S. Hayashida, and S. Imamura, "Deuterated polysiloxane optical waveguides with low loss and high environmental stability," Japan International Electronic Manufacturing Technology (IEMT) Symposium, Omiya, paper TB1-4, Proceedings pp. 260-263, December 1995.
S. Tomaru, T. Watanabe, M. Hikita, M. Amano, Y. Shuto, H. Itoh, I. Yokohama, and M. Asobe, "Quasi-phase-matched second harmonic generation in an electro-optic polymer waveguide," OSA/ACS Topical Meeting on Organic Thin Films for Photonic Applications, Portland, Oregon, paper ThB5, Technical Digest pp. 412-415, September 1995.
T. Watanabe, M. Amano, M. Hikita, Y. Shuto, and S. Tomaru, "Novel functional waveguides formed using an electro-optic polymer," International Workshop on Advanced Materials for Multifunctional Waveguides, Makuhari, Proceedings pp. 114-117, July 1995.
M. Hikita, M. Usui, T. Watanabe, S. Sugawara, M. Amano, and S. Imamura, "Low-loss polymeric optical waveguide with high environmental stability," 10th International Conference on Integrated Optics and Optical Fiber Communications (IOOC 1995), Hong-Kong, paper TuD1-4, Proceedings vol. 1, pp. 69-70, June 1995.
T. Watanabe, M. Amano, M. Hikita, Y. Shuto, and S. Tomaru, "Novel 'serially-grafted' connection between functional/passive polymer waveguides," 5th Optoelectronics Conference (OEC 1994), Makuhari, paper 15B2-2, Technical Digest pp. 336-337, July 1994.
M. Amano, M. Hikita, Y. Shuto, T. Watanabe, S. Tomaru, M. Yaita, and T. Nagatsuma, "Diazo dye attached electro-optical polymer and its application to waveguide devices and electro-optical sampling," OE/LASE 1994, Los Angeles, California, paper 2143-07, invited, Proceedings of SPIE, vol. 2143, pp. 68-79, January 1994.
M. Hikita, T. Watanabe, Y. Shuto, M. Amano, R. Yoshimura, S. Tomaru, and H. Kozawaguchi, "Fabrication of vertically stacked coupler using electro-optic polymer," OSA/ACS Topical Meeting on Organic Thin Films for Photonic Applications, Toronto, paper FC5, OSA Technical Digest Series 17, pp. 314-317, October 1993.