Compact polarization-independent quasi-adiabatic 2×2 3 dB coupler on silicon

Abstract

We demonstrate a quasi-adiabatic polarization-independent 2×2 3 dB coupler based on the silicon-on-insulator platform. Using a quasi-adiabatic taper design for the mode evolution/coupling region, the TE mode evolution is accelerated, and the TM mode coupling is achieved at a short coupling length. The measured working bandwidth is 75 nm with a compact mode evolution/coupling region of 11.7 μ m.