Peking University has made significant progress in the field of photonic chip clocks

Recently, the research team of Chang Lin from the School of Electronics of Peking University and the research team of Li Wangzhe from the Aerospace Information Research Institute of the Chinese Academy of Sciences published a research article entitled "Microcomb synchronized optoelectronics" online in Nature Electronics, realizing the application of photonic chip clocks in information systems for the first time in the world. This technology is based on mass-produced ultra-low loss silicon nitride photonic chips, which generate high-precision and low-noise clock signals through optical frequency combs, breaking through the performance bottlenecks of traditional electronic chips in terms of clock bandwidth, energy consumption, and noise. This provides an important solution for the development of future ultra high speed chips.

In today's information age, the demand for high-speed and broadband performance in electronic systems is exploding. Traditional electronic technology has many problems when generating high-frequency signals, such as narrow bandwidth, easy signal distortion, and high power consumption. In optoelectronic systems, the frequency of optical synthesized signals and electronic clocks is severely mismatched, leading to synchronization difficulties. This not only reduces processing accuracy, but also slows down information transmission speed. Although there have been synchronization strategies before, most of them require additional hardware and complex operations, making them difficult to widely apply. To overcome these challenges, the research team has jointly developed an oscillator based on on-chip micro combs for synchronization in optoelectronic systems. This oscillator combines micro comb and self injection locking technology with integrated ultra-high Q-value resonators to synthesize microwave signals covering from megahertz to 105 GHz, providing a shared time-frequency reference for the system and enabling natural synchronization of optical and electronic signals.

The research team further demonstrated a multi band sensing integrated system based on this chip, which achieved multiple functions in different electromagnetic wave bands such as 5G, 6G, and millimeter wave radar through a single chip. Flexible switching between sensing and communication modes. This innovative design not only simplifies the hardware structure, but also significantly reduces the complexity and cost of the system. The system achieves centimeter level perception accuracy and 6G communication with modulation formats up to 256-QAM.

Time frequency synchronization strategy for optoelectronic systems

In the future, this technology is expected to be widely applied in multiple fields. For example, in processor chips, this solution can increase the clock frequency to over 100G, providing far more computing power than current chips; In mobile base stations, it can significantly reduce the energy consumption and cost of devices; In the field of autonomous driving, the integrated design of millimeter wave radar will help improve perception accuracy and response speed. The breakthrough of this technology will bring revolutionary changes to the fields of communication and perception, promoting the rapid development of related industries.

The co first authors of this paper are Zhang Xiangpeng, a postdoctoral fellow at the School of Electronics, Peking University, and doctoral students Zhang Xuguang and Chen Yujun. Chang Lin, a researcher from the School of Electronics of Peking University, Li Wangzhe, a researcher from the Aerospace Information Institute of the Chinese Academy of Sciences, and Professor John E. Bowers of the University of California, Santa Barbara, are the co corresponding authors of the paper. The main collaborators also include Professor Wang Xingjun and Professor Hu Weiwei from the School of Electronics, Peking University, postdoctoral researcher Lao Chenghao, doctoral students Zhou Zixuan and Huang Jiahui, Dr. Warren Jin from the University of California, Santa Barbara, Associate Researcher Dong Jingwen, Associate Researcher Ma Weichao, and First level Assistant Researcher Liu Chenyu from the Institute of Aerospace Information, China Academy of Aerospace Sciences. This work was completed by the State Key Laboratory of Regional Optical Fiber Communication Network and New Optical Communication System of School of Electronics, Peking University as the first unit.

Source: opticsky