Polarization controlling by FPGA for quantum security communication

The polarization of photons in the optical fiber cannot maintain stable for long distance. Therefore, polarization control is necessary for the fiber-based polarization-encoded quantum security communication system to guarantee correct key generation. With the development of the practical quantum communication, field programmable gate array (FPGA) has played an important role in the information processing and system operation due to its advantage of high efficiency, high integration and high security. A polarization control scheme and polarization initialization is presented and applied to the BB84 protocol based on FPGA to stabilize photon polarization in the fiber. 90% of a code-consuming is higher than 65% of the maximum value in the computer control center. With the same codec and error correction mode, if who has more time consuming for coding, then he will get more efficient key generation. FPGA, single photon detection, and electric polarization controller (EPC) mechanism can be unified and integrated to achieve the miniaturization of quantum polarization controlling.