平板偏振膜的角度特性研究

当入射光倾斜入射到平板偏振膜上时,在两种偏振光的反射带边缘处出现P偏振光高透而S偏振光高反的情况.利用F-P结构的膜系设计了偏振膜.随着入射角的增大,S光的带宽、消光比及参考波长线性增大,而膜层中电场强度的最大值和界面处的电场强度均减小,只有P偏振光的变化特性跟布儒斯特角有关.分析膜层的界面特性和膜层中的缺陷分布情况,可得偏振膜P偏振光的阈值随入射角的增大而增大.结果表明,在P光透过率可使用的范围内,入射角越大,消光比越大,场强在膜层中的分布越低,但P偏振光的透过率有所降低.

Investigation on the Characteristics of the Plate Polarizer

When light enters plate polarizer at a certain angle,p-polarization,high transmission,s-polarization and high reflection appear on the edge of reflective band.The polarizer is designed with stack formula of F-P structure.With the angle of incidence increasing,the band-width,extinction ratio and reference wavelength also increase,and at the same time,the maximum electric-field intensity(EFI) in the inner of layer and the EFI at the interface drops off.Only the varying characteristic of p-polarization is associated with the Brewster's angle.By analyzing the interface properties and defect distribution in layers,it is found that the p-polarization laser-induced damage threshold of polarizer increases as the incident increases.The results indicate that in the allowable range of p-polarization,the bigger the angle of incidence on polarizer is,though the transmittance of p-polarization decreases slightly,the better the extinction ratio is and the lower the EFI in the layer is.