部分偏振部分相干光光栅衍射场的偏振特性和角相关研究

Study of Grating Diffractive Field's Degree of Polarization and Angular Coherence of Partially Polarized and Coherent Beams

为了研究部分偏振部分相干光光栅衍射场的衍射特性,利用部分偏振部分相干光的光束相干-偏振(BCP)矩阵,推导出了部分偏振部分相干光通过任意偏振光栅后,衍射场的偏振度及场中衍射级次角相关的一般解析表达式。以部分偏振的高斯-谢尔模型光束(PGSM)为例,数值分析了偏振光栅TE和TM波的复振幅透过率、入射光束的光学参量对衍射场偏振度和场中各衍射级次的角相关的影响。计算结果表明,部分相干光透过偏振光栅后的其衍射光场是一非均匀、周期变化的部分偏振相干光场;场中对称级次的角相干值对应相等,且随衍射级次序数的增大而缓慢递减至零。

In order to study the grating diffractive field＇s characteristics of the partially polarized and coherent beams, an analytic expression of polarization degree and angular correlation of partially ploarized and coherent beams through polarized gratings is derived based on the beam coherentce-polarization （BCP） matrix approach of partially coherent beams. And then the partially polarized and coherent Gausian-Schell beam （PGSM） is taken as a numerical example to study the influence of the polarized grating TE and TM complex transmission and some parameters of the incident PGSM on the polarization degree of the diffraction field and the diffractive orders＇s angular correlation in details. It is shown that the PGSM＇s diffractive field is an uneven and periodically changed partially coherent field, and the symmetrical diffraction order＇s angular coherence is equal and decreases to zero along with the increase of diffraction orders.