按晶体波片的快轴与水平方向成0°、45°、0°、45°顺序排列构造四波片偏振控制器。固定各波片的快慢轴,利用模拟退火算法进行反馈控制,通过改变各波片的相位得到所需的偏振态。仿真结果说明,利用模拟退火算法进行负反馈控制,其收敛速度较快,收敛后光强波动小于2%;该控制器能在各波片相移范围限制在0～2π情况下实现偏振态的无端控制。为消除可能出现的复位死角,在模拟退火算法基础上加入强制无端复位方法,复位过程稳定。控制过程中该控制器各波片的相移步长可变,但寻优过程中最大步长不超过3.36°,强制复位过程中最大步长不超过18°,因此控制电压的变化平缓。

A four-wave-plate electrooptic polarization controller (PC) is constructed with their fast axes oriented alternately at 0°, 45°, 0°, 45° with respect to horizontal. The simulated annealing feedback controlling algorithm is applied to the controlling process to get the desired output polarization state. Simulating results show that this polarization controller is endless and the plate phase range can be limited within 0 to 2π. Using this controlling algorithm the controller can converge rapidly and the fluctuation of light intensity is less than 2%. To ensure the endless property of the controller a coercing reset method is introduced and here the reset process is stable. In searching the optimal value, the phase shift step of plates is variable but less than the maximum step of 3.36° while the step is fixed in 18° for the coercing reset.