最小二乘法求解非线性方程的物理偏振参量测量

Measurement of Physical Polarization Parameters by Solving Nonlinear Estimation Equation with Least-Square Method

提出了基于最小二乘优化系统的估值方法测量求解光器件物理偏振参量。对于输入偏振态可测或非可测的系统，在建立相应的估值解析方程和适当的测量条件基础上，此测量方案均是简单易行的。对以旋转波片为偏振发生器的测量系统的估值误差进行了仿真和分析。仿真表明，选取较多的测量次数，且旋转波片延迟为37c／4附近时，可得到较小的估值误差。基于系统估值算法，针对输入偏振态可直接测量的情况建立了实验系统并进行估值。实验表明，估值得到的物理偏振参量的标准差在0．0011--0．0103内。

The system estimation by least square optimization is employed to obtain physical polarization parameters of optical devices. The method has proven to be flexible and convenient for measuring polarization parameters in dif- ferent systems where the input state of polarization （SOP） of the devices is either measurable or not, providing the analytical estimation equations and adequate measurements are available. The estimation error in the measurement system with a rotating wave-plate （WP） as the polarization state generator is analyzed and simulated. Better estima- tion precision can be obtained by involving more SOP measurements in estimations and choosing a WP with retardance around 3rr/4. Experiment based on the conception is demonstrated to estimate the polarization parameters of a fiber polarization controller with measurable input SOP. The standard deviations of estimated polarization parameters are within 0. 0011 -0. 0103.