polish-the-followingnEquation-2-indicates-that-SPRS-can-be-equivalent-to-a-combination-of-45°-rotator-PSR-and-PS-with-fixed-relative-phase-where-PS-with-fixed-relative-phase-can-move-phase-onto-an-adjustable-phase-shift-arm-In-this-work-we-use-the-bi

Equation 2 demonstrates that SPRS can be achieved through a combination of a 45° rotator, PSR, and PS with a fixed relative phase. The PS with a fixed relative phase can transfer phase onto an adjustable phase shift arm. In this study, we utilized the bi-level taper + symmetric Y branching structure of TM0-TE1 to implement the function of SPRS. This innovative design allows for the use of a general phase shifter (PS) rather than a polarization-dependent phase shifter (PDPS). Consequently, the length of the phase shift arm is reduced from over 700 μm to 100 μm, resulting in a smaller device size. Furthermore, this structure effectively increases the bandwidth of the device since the longer the phase shift arm, the smaller the bandwidth of the device [10].