An endless polarization stabilizer based on DSP system

An endless polarization stabilizer based on DSP system is reported. It can transform the state of polarization (SOP) of optical signal to any desired SOP and maintaining output signal at the desired SOP. Feedback controlling method is applied to the proposed polarization stabilizer. We design a target function relates to current SOP and the desired SOP in transmission link. It has only one extremum when SOP in transmission link is exactly the same with the desired SOP. Particle swarm optimization algorithm is employed to search the extremum point. To investigate performance of the proposed polarization stabilizer, HP11896A polarization controller is used as polarization scrambler. We test performance of the polarization stabilizer under rate 1 (∼16 rad/s), 4 (∼33 rad/s), and 8 (∼65 rad/s), separately. Under the existing condition of our laboratory, the developed polarization stabilizer has the ability of stabilization up to 65 rad/s SOP changes (rate 8).