Optimizing the Operation of $\hbox{LiNbO}_{3}$ -Based Multistage Polarization Controllers Through an Adaptive Algorithm

The LiNbO
₃
-based polarization controller is widely used, but it needs to be calibrated in order to cancel the remaining birefringence. The calibration of the LiNbO
₃
polarization controller is untrivial because there are several stages, and for each stage, at least four parameters, including
VA
, Bias,
VC
, Bias,
V

₀
, and
V

_¿
, need to be calibrated. A smart calibration approach is presented theoretically and experimentally. The particle swarm optimization (PSO) algorithm is used as an adaptive searching algorithm. The experiment results show that the PSO algorithm is powerful to optimize the operation of LiNbO
₃
-based multistage polarization controllers. It takes only less than 1 min for all the stages of the polarization controller to be thoroughly calibrated.