Fast Polarization Switch for Polarization-based Quantum Communication

We present a complete optoelectronic unit for polarization visualization, switching and control. The system is based on a Field Programmable Gate Array (FPGA) unit and comprises: an acquisition unit containing an analog polarimeter and digital-to-analog converters; an FPGA capable of implementing an optimal algorithm for three-stage arbitrary polarization tracking; and an electronic driver with analog-to-digital converters capable of interfacing with Lithium-Niobate-based Polarization Controllers. The results, determined via simulation of real-parameter devices, show that fast polarization switch is achievable.