Crossing-free on-chip 2 × 2 polarization-transparent switch with signals regrouping function

• Main Authors: Sun, Chunlei, Lai, Yaxiao, Yu, Yu, Fu, Songnian, Shum, Perry Ping, Zhang, Xinliang
• Other Authors: School of Electrical and Electronic Engineering
• Format: Article
• Language: English
• Published: 2020
• Subjects: Engineering::Electrical and electronic engineering; Integrated Optics Devices; Optical Switching Devices
• Online Access: https://hdl.handle.net/10356/138713
• Institution: Nanyang Technological University

We propose and demonstrate an on-chip 2×2 polarization-transparent switch for simultaneously handling two-group polarization-division multiplexing (PDM) signals. By introducing the polarization-transparent power splitter/combiner (PPS/PPC), waveguide crossings such as those in conventional PDM switches can be avoided and, thus, the insertion losses and complexity of the device can be reduced. Furthermore, each input polarization tributary can be independently switched and routed thanks to the output selectivity of the PPS/PPC. Thus, not only a basic switch between the dual-group PDM signals, but also a precise four-channel-signal regrouping can be achieved, enabling a complete and non-redundant switching functionality. A polarization extinction ratio larger than 15 dB with reasonable insertion losses is experimentally observed. Clear and open eye diagrams can be obtained with less than 1 dB power penalties for all the measured paths.