On May 18, 2022, the Center and the group of Prof. John E. Bowers at the University of California, Santa Barbara published the article "Microcomb-driven silicon photonic systems" online in Nature. It is the first time in the world to report a new type of silicon-based optoelectronic on-chip integrated system driven by an integrated microcavity comb, indicating that the research team has finally conquered this worldwide problem after three years of collaborative research.
Screenshot of the paper
Optical combs, also known as optical frequency combs, have long been an important research hotspot in the international optics community because of their wide range of applications. Prof. John Lewis Hall of the National Institute of Standards and Technology (NIST) and Prof. Theodor Hänsch of the Max Planck Institute of Quantum Optics (MPI), Germany, were awarded the 2005 Nobel Prize in Physics for their outstanding contributions to optical combs. In recent years, chip-scale optical combs (microcavity optical combs) have greatly expanded their range of applications due to their compact size and low cost. However, in most system-level applications based on microcavity optical combs, only the microcavity itself is an integrated device, and the rest of the components (including pump lasers, passive/active processor devices, and circuit control units) are not integrated. This greatly diminishes the advantages offered by microcavity optical comb chipization in terms of cost, size and power consumption。Therefore, integration at the level of integrated optical comb system is of great significance for the practicalization and popularization of optical frequency comb technology.
At the same time, in the past 20 years, silicon-based optoelectronic integrated chip technology (silicon optical) with the help of mature CMOS process, can be large-scale integration of traditional optical systems required for the functional devices, and greatly enhance the speed and capacity of on-chip information transmission and processing. It can bring transformative breakthroughs for next-generation data centers, communication systems, high-performance computing, automated driving and other fields. It is universally recognized as the core technology for the functional upgrading of modern information systems and industrial layout, and is the main position for competition in the world's optoelectronics field. Currently, as the application market expands and the system scale increases dramatically, the system-on-chip architecture of silicon-based optoelectronics is evolving into a multi-channel and highly parallel architecture, which is accompanied by an increasing demand for low-cost and high-stability parallel light sources. However, due to the silicon material itself does not emit light, the realization of silicon-based lasers has been a world-wide problem, and the development of a multiplexed parallel silicon-based light source on a silicon-based optoelectronic chip is more widely recognized as one of the biggest bottlenecks in this field.
Under the guidance of Prof. Xingjun Wang, the research team of the center provides the required light source brain to the silicon-based optoelectronics integration chip by directly pumping the integrated microcavity optical frequency comb by semiconductor lasers, combining with the industrially mature and reliable integration solution of silicon-based optoelectronics integration technology to complete the efficient parallelization of the large-scale integration system. The team utilizes this highly integrated system to realize T-bit rate micro-communications and sub-GHz microwave photonic signal processing, proposing a new architecture for high-density, multi-dimensional multiplexed micro-communications and microprocessing chip-scale integrated systems and pioneering the development of the next-generation, multi-dimensional, silicon-optical integrated microsystems sub-discipline. The related research results are expected to be directly applied to data centers, 5/6G communications, automated driving, optical computing, etc., providing a new research paradigm and development direction for the next-generation on-chip optoelectronic information system.
System-on-chip diagram of silicon-based integrated optoelectronics driven by integrated microcavity optical combs
The co-first authors of the paper are Hao-Wen Shu, a postdoctoral fellow of the Center's Boshin Program; Dr. Chang Lin of the University of California, Santa Barbara (currently working at the School of Electronics of Peking University as an assistant professor and researcher, an independent PI and forming a group); and Yuan-Sheng Tao and Bi-Tao Shen, doctoral students of the Center. Prof. Xingjun Wang and John E. Bowers are the co-corresponding authors of the paper. Academician Shaohua Yu of Pengcheng Laboratory participated in this work and provided important guidance. Key collaborators also include Dr. Wei-Qiang Xie (now Associate Professor at Shanghai Jiaotong University) and Ph.D. student Andrew Netherton at the University of California, Santa Barbara, Center Ph.D. students Ming Jin, Zihan Tao, and Xuguang Zhang, and post-doctoral fellows Ruixuan Chen, Bowen Bai, and Jun Qin (now Associate Professor at the Beijing University of Information Science and Technology). This work is completed by the State Key Laboratory of Regional Optical Fiber Communication Networks and New Optical Communication Systems, School of Electronics, Peking University, as the first unit, and is also an important result of the cooperation with Pengcheng Laboratory, which is one of the core contents of the major research tasks of the Circuits and Systems Department of Pengcheng Laboratory.
Link to the original paper:
https://www.nature.com/articles/s41586-022-04579-3
