Fellows
/Senior Distinguished
Researchers
/Distinguished
Researchers

Awards

• 2025 Stanford/Elsevier Top 2% Scientists List
• 2024 NTT President's Award
• 2024 Stanford/Elsevier Top 2% Scientists List
• 2022 IEICE Young Researchers Award
• 2021 Optical Communication Systems (OCS) Young Researchers Award

Academic Activities

• 2026, Lead Organizer of OFC2026 Workshop "Toward Holistic Network and Environment Visibility: Are Fiber Sensing and Tomography Ready to Deliver in Real Networks?"
• 2026, Technical Program Committee Member, Optical Fiber Communication Conference (OFC), Subcommittee S4 (Fiber Sensing and Microwave Photonics)

Relevant News Releases

• 2025, Achieved automatic configuration of 1 Tbps-class optical network on IOWN APN based on open specifications - Demonstrated on-demand instant provisioning of optical wavelength circuits at OFC2025 (https://group.ntt/jp/newsrelease/2025/03/31/250331a.html)
• 2024, Developed technology to visualize optical fiber transmission link conditions end-to-end without measurement instruments, and achieved world-first, world-highest accuracy field demonstration - Advancing toward optical network digital twins, enabling rapid optical connection/maintenance (https://group.ntt/jp/newsrelease/2024/08/20/240820a.html)
• 2024, Live demonstration of 400 Gbps/800 Gbps IOWN APN using photonics-electronics convergence technology and open standards with multi-vendor products at OFC2024 - Connecting distributed data centers with low latency and low power through all-optical transmission (https://group.ntt/jp/newsrelease/2024/03/26/240326a.html)

Selected Publications

• (Post-deadline paper) T. Sasai, Y. Nakajima, M. Takahashi, R. Kaneko, M. Nakamura, A. Matsushita, F. Hamaoka, E. Yamazaki "First Coherent DSP and Pluggable Transceiver Capable of Distance-Resolved, Longitudinal Power Monitoring," Optical Fiber Communications Conference and Exhibition (OFC) 2026, Los Angeles, USA, 2026.
• (Post-deadline paper) T. Sasai, M. Takahashi, F. Hamaoka, M. Nakamura, S. Sugawara, S. Yamamoto, H. Nishizawa, Y. Sone, and E. Yamazaki, "Tens-of-Metre Resolution Longitudinal Power Monitoring over 302-km Fibre Link," European Conference on Optical Communication (ECOC) 2025, Copenhagen, Denmark, 2025.
• (Top-scored paper, upgraded to invited status) T. Sasai, K. Anazawa, D. Briantcev, D. Dass, S. Ali, G. Borraccini, Y. Kobatake, H. Ishihara, E. Kenny, G. Liu, T. Mano, M. Nakamura, H. Nishizawa, Y. Sone, E. Yamazaki, Y. Kisaka, K. Takasugi, K. Asahi, M. Ruffini, D. Kilper, "Optical Network Tomography over Live Production Network in Multi-Domain Environment," European Conference on Optical Communication (ECOC) 2025, Copenhagen, Denmark, 2025.
• T. Sasai, G. Borraccini, Y. K. Huang, H. Nishizawa, Z. Wang, T. Chen, Y. Sone, M. Takahashi, T. Matsumura, M. Nakamura, E. Yamazaki, K. Takasugi, T. Wang, and Y. Kisaka, "Optical Link Tomography: First Field Trial and 4D Extension," J. Lightw. Technol., 43(24), pp. 10776-10787, 2025.
• (Post-deadline paper) T. Sasai, G. Borraccini, Y. K. Huang, H. Nishizawa, Z. Wang, T. Chen, Y. Sone, T. Matsumura, M. Nakamura, E. Yamazaki, Y. Kisaka, "4D Optical Link Tomography: First Field Demonstration of Autonomous Transponder Capable of Distance, Time, Frequency, and Polarization-Resolved Monitoring," Optical Fiber Communications Conference and Exhibition (OFC) 2024, San Diego, USA, 2024.
• T. Sasai, M. Takahashi, M. Nakamura, E. Yamazaki, and Y. Kisaka, "Linear Least Squares Estimation of Fiber-Longitudinal Optical Power Profile," J. Lightw. Technol., 42(6), pp.1955-1965, 2024.
• (Invited) T. Sasai, E. Yamazaki, and Y. Kisaka, "Performance Limit of Fiber-Longitudinal Power Profile Estimation Methods," J. Lightw. Technol., 41(11), pp.3278-3289, 2023.
• T. Sasai, M. Nakamura, E. Yamazaki, S. Yamamoto, H. Nishizawa, and Y. Kisaka, "Digital Longitudinal Monitoring of Optical Fiber Communication Link," J. Lightw. Technol., 40(8), pp.2390-2408, 2022.

Keywords

Optical Fiber,Tomography,Coherent DSP,Longitudinal Monitoring,Optical Network Digital Twin