Reset-free Integrated Polarization Controller Using Phase Shifters

An endless, reset-free polarization controller using phase shifters for tuning is proposed. By avoiding the need for tunable polarization mode converters, simple fabrication processes and a large range of material systems can be used since neither the electro-optic effect nor a rotatable birefringence axis are necessary for device operation. The proof-of-concept is demonstrated by implementing the equivalent of a rotating waveplate using silica-on-silicon waveguides and thermo-optic phase shifters. The polarization controller is shown to have excellent tolerance to fabrication variations.