Polarization-Independent Silicon Nitride 3-dB Coupler for Potential Matrix Switches Application

A polarization-independent 3-dB coupler was experimentally demonstrated with a 580-nm-thick, 700-nm-wide Si 3 N 4 waveguide. By consisting a MZI structure, both TE and TM light can output from the cross port, confirming the polarization-independent performance of the device.