Developments of ultra-high-speed VCSELs using coupled cavities

2023 Fiscal Year Final Research Report

• Project/Area Number: 21H04554
• Research Category: Grant-in-Aid for Scientific Research (A)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Medium-sized Section 21:Electrical and electronic engineering and related fields
• Research Institution: Tokyo Institute of Technology
• Principal Investigator: Koyama Fumio 東京工業大学, 科学技術創成研究院, 特任教授 (30178397)
• Project Period (FY): 2021-04-05 – 2024-03-31
• Keywords: 半導体レーザ / データセンタ / 光インターコネクト / 光通信

Outline of Final Research Achievements

We have established an ultra-high-speed modulation platform that significantly expands the modulation bandwidth by integrating a miniature resonator laterally on a surface-emitting laser, which is the main light source for optical interconnects in data centers, and using the optical feedback effect. Since the micro-cavity VCSEL does not require an increase in the driving current needed for conventional high-speed operation, low power consumption has also been achieved. In addition to clarifying the theoretical modulation speed limit, we have achieved a modulation bandwidth of 50 GHz, more than twice that of existing technology, ultra-high-speed operation of 160 Gbps, and low power consumption operation of less than 1/5. Furthermore, by extending the emission wavelength to the 1.1 μm band, we have extended the link distance of single-mode optical fiber transmission to more than 2 km, demonstrating the applicability of this technology to hyper-scale data center networks.

Free Research Field

光エレクトロニクス

Academic Significance and Societal Importance of the Research Achievements

機器間の光リンクの高密度実装、低消費電力化のために，次世代超小型光トランシーバの開発競争が世界中で活発に繰り広げられているが，大容量化，スケーラビリティ，小型実装，低消費電力化への要求を満たす解が見出されていない．近い将来100Gbps超の高速化のニーズは大きいものの，現状技術は25Gbpsの伝送速度に留まっていた．生成AIの進展により，データセンタ内のリンク速度の拡充と消費電力の低減は喫緊の課題である．本研究により，低消費電力化と高速化を両立させる面発光レーザからなる超高速光リンク技術を開発する学術的・産業上の意義は極めて大きい．