Calibration free broadband polarization-insensitive silicon optical switch

We propose and demonstrate a polarization-insensitive optical switch on a 220 nm silicon-on-insulator (SOI) platform. The device utilizes a Mach-Zehnder interferometer (MZI) structure composed of an ultra-wide waveguide with nearly identical effective indices and thermo-optical coefficients for the transverse electric (TE) modes. A mode rotator based on mode hybridization facilitates the conversion between TM₀ and TE₁. The fabricated device exhibits polarization-insensitive characteristics within the wavelength range of 1500-1600 nm, with an extinction ratio exceeding 18 dB, insertion loss below 1.9 dB, and a switching power consumption of 33.2 mW for the TE mode and 33.8 mW for the TM mode, differing by less than 2%. Additionally, the calibration power for the two polarizations is 1.0 mW and 1.7 mW, both less than 5% <b><i>P</i></b>_{<b><i><i>π</i></i></b>}.