Compact reconfigurable on-chip polarization beam splitter enabled by phase change material

In this paper, we present the design of a compact reconfigurable polarization beam splitter (PBS) enabled by ultralow-loss phase-changing Sb 2 Se 3 . By harnessing the phase-change-mediated mode coupling in a directional coupler (DC), guided light with different polarizations could be routed into different paths and this routing could be dynamically switched upon the phase change of Sb 2 Se 3 . With an optimized DC region, the proposed PBS demonstrates efficient polarization splitting with crosstalk less than −21.3 dB and insertion loss less than 0.16 dB at 1550 nm for both phase states of Sb 2 Se 3 , and features energy efficient property benefitting from the nonvolatile phase change of Sb 2 Se 3 , which holds great potentials for on-chip applications involving polarization control, including polarization-division multiplexing system, quantum photonics, microwave photonics, etc.