With the rapid advancement of artificial intelligence and high-performance computing, global data traffic is experiencing explosive growth, posing unprecedented challenges to both information transmission speed and energy efficiency within data centers. Traditional optical communication technologies are facing bandwidth bottlenecks and power consumption barriers, urgently requiring the development of a new generation of high-speed, efficient, and highly integrated optical interconnect technologies. Optical frequency combs, capable of simultaneously generating multiple phase-locked wavelengths for parallel data transmission, are considered a disruptive solution to these challenges. However, achieving practical optical frequency comb sources with ultra-wide bandwidth, ultra-high temperature stability, and ultra-long operational lifetimes has remained a major industry challenge.
Recently, a research team led by Professor Chen Siming from the Institute of Semiconductors, Chinese Academy of Sciences, in collaboration with Huisi Optoelectronics, Shenzhen University of Technology, and the National Innovation Center for Information Optoelectronics, achieved a breakthrough in high-speed quantum dot mode-locked optical frequency comb technology for optical communications. Through innovative co-doping techniques for semiconductor quantum dot materials and collision-pulse mode-locking schemes, the team successfully developed a 100 GHz quantum dot optical frequency comb laser capable of stable operation at extreme temperatures up to 140°C. This device achieves breakthroughs in operating temperature, transmission capacity, and reliability, providing a critical light source solution for future Tbps-level optical interconnects.
The research demonstrates outstanding comprehensive performance metrics: at room temperature (25°C), the laser achieves a 3dB optical bandwidth of 14.312 nm, capable of generating 26 channels. Each channel can carry a 128 Gb/s PAM-4 modulated signal. The device maintains stable mode-locking up to 140°C. At 85°C-an industrial-grade high-temperature standard-its key performance metrics show negligible degradation, supporting stable operation of 22 channels for a total data throughput of 2.816 Tb/s. Simultaneously, its energy consumption per bit transmitted is as low as 0.394 pJ at 25°C and 0.532 pJ at 85°C. Accelerated aging tests exceeding 1,500 hours at 85°C indicate a Mean Time To Failure (MTTF) of 207 years, fully meeting stringent commercial application requirements.
This work not only experimentally demonstrates the feasibility of simultaneously achieving ultra-wideband, ultra-high-temperature, ultra-long-life, and high-integration quantum dot optical frequency combs on a single chip, but also provides a powerful, cost-effective light source implementation path for optical interconnect systems in next-generation data centers and artificial intelligence computing clusters.
