Experimental Demonstration of a High Efficiency Polarization Splitter Based on a One-Dimensional Grating With a Bragg Reflector Underneath

A one-dimensional grating serving both as a polarization beam splitter and a vertical coupler for silicon photonic circuits is designed, fabricated, and characterized. Bragg reflectors are employed to improve greatly the coupling efficiency. Over 50% efficiency for both polarizations are achieved experimentally, and the extinction ratio between them is also high ( -20 dB).