Polarization-Insensitive Operation of Lithium Niobate Mach–Zehnder Interferometer With Silica PLC-Based Polarization Diversity Circuit

We demonstrate the polarization-insensitive operation of a Mach-Zehnder interferometer (MZI)-based lithium niobate switch with a silica waveguide polarization beam splitter. The splitter is composed of an MZI with a half wave plate installed in one arm, and exhibits a polarization extinction ratio of more than 15 dB. The switch functions for both polarizations with an extinction ratio of more than 20 dB, a polarization-dependent loss of 0.1 dB and a switching speed of 40 ps.