Reconfigurable polarization processor based on coherent four‐port micro‐ring resonator

作者：Yi Dan, Jiapeng Luan, Yi Wang, Hon Ki Tsang · 发表于：Nanophotonics · 年份：2023 · DOI：10.1515/nanoph-2023-0031 · 被引用次数：14 · 研究领域：Neural Networks and Reservoir Computing、Optical Network Technologies、Photonic and Optical Devices

Abstract Polarization processors with versatile functionalities are needed in optical systems, which use or manipulate polarized light. In this paper, we propose and realize an integrated polarization processor based on a coherent 4‐port micro‐ring resonator. The arbitrary unknown polarization state is input to the polarization processor via a 2‐dimensional grating coupler (2DGC), which serves as a polarization beam splitter. The coherent 4‐port micro‐ring resonator (MRR) operates as a unitary processor and is formed by one crossbar micro‐ring resonator and two thermally tunable phase shifters, one of which tunes the micro‐ring while the other tunes the coherent interference between the two inputs from the 2DGC. The 4‐port system can be used to control the input polarization states that appear at the two output ports and, therefore, can be used to implement a multi‐function polarization processor, including polarization descrambler, polarization switch, polarizers, and polarization analyzer (both division of space (DOS) and division of time (DOT)). In this paper, we experimentally demonstrate the use of coherent 4‐port MRR for polarization mode switching and for polarization mode unscrambling. The polarization unscrambler was capable of separating two polarization‐multiplexed 40 GHz data lanes from the input fiber with crosstalk levels below −21 dB and is suitable for use in the receiver for polarization‐multiplexed direct‐detection optical communications systems. The same ph...