可调谐液晶红外滤光片的光学特性分析

可调谐红外滤光片是高分辨率红外成像仪谱段识别和分光的重要光学器件。采用琼斯矩阵方法对平行向列相和90°扭曲向列相液晶法-珀红外滤光片的本征偏振态及光学特性进行了研究。结果表明,当非偏振光垂直入射时,平行向列相液晶法-珀滤光片在任何电压下两组本征偏振态均不发生模式混合,具有偏振敏感性;90°扭曲向列相液晶法-珀滤光片在电压较低时具有偏振敏感性,当电压大于三倍Freedericksz阈值电压时,两组本征偏振态发生模式混合,偏振敏感性消除。

Optical performance analysis of tunable liquid crystal infrared filter

Tunable infrared filters are important optical components for high resolution infrared imagers in spectral band recognition and beam-split.The optical performance and the eigenmodes of a parallel and a 90° twist nematic liquid crystal Fabry-Perot filter are analyzed based on the Jone matrix method.Results show that when the normal incidence light is unpolarized light,for the parallel one,the two modes do not merge together at any voltage,it is polarization sensitive;For the 90° twist one,it is polarization sensitive at low voltage,however,the two modes merge together when the applied voltage exceeds～3X of the Freedericksz transition threshold,it is polarization insensitive.