Photonic signal processing is essential in the optical communication and optical computing. Numerous photonic signal processors have been proposed, but most of them exhibit limited reconfigurability and automaticity. Multipurpose chip-scale photonic signal processors with the ability of programming and self-configuration are highly desirable since they show great advantages in size, cost, reconfigurability and intelligence.
Fig.1. (a) Special-purpose processors for optical matrix computing and polarization processing respectively. (b) Self-configuring example for the smart processors.
Prof. Xinliang Zhang and Prof. Jianji Dong from Wuhan National Laboratory for Optoelectronics, had demonstrated two special-purpose processors for optical matrix computing and polarization processing respectively. The optical matrix computing processor is capable of performing fundamental matrix computations including XB=C, AB=X and AX=C, where A, B, C are known matrices, and X is the matrix to be solved. An optical PageRank algorithm is further demonstrated based on the matrix computing processor for the first time. It offers an optical method to achieve matrix computations and PageRank algorithm. The polarization processor can finish multiple polarization processing functions, including polarization multiple-input-multiple-output descrambler, polarization controller and polarization analyzer, which are the basic building blocks of polarization processing. More functions can be realized by using an additional two-dimensional output grating. A numerical gradient descent algorithm is employed to self-configure and self-optimize these functions. Our demonstration suggests great potential for chip-scale reconfigurable and fully programmable photonic computing and polarization processors with artificial intelligent algorithm.
The works have been published by IEEE journal of selected topics in quantum electronics and Nanophotonics respectively. The works were partially supported by National Key Research and Development Project of China (2018YFB2201901), by national natural science foundation of china (61622502, 61805090); by china postdoctoral science foundation (2017M622419); by State Key Laboratory of Advanced Optical Communication Systems and Networks, Shanghai Jiao Tong University, China (2019GZKF03002); by Hong Kong Research Grants Council (PolyU152471/16E); and by Hong Kong Scholars Program 2018 (XJ2018018).
References:
[1]H. Zhou, Y. Zhao, G. Xu, X. Wang, Z. Tan, J. Dong, and X. Zhang, "Chip-scale optical matrix computations for PageRank algorithm," IEEE Journal of Selected Topics in Quantum Electronics, 1-1 (2019).
[2] H. Zhou, Y. Zhao, Y. Wei, F. Li, J. Dong, and X. Zhang, "All-in-one silicon photonic polarization processor," Nanophotonics, (2019).
