电压调谐液晶滤光片的研究

对以液晶为腔内物质的液晶法布里珀罗调谐滤光片进行了改进 ,在原来法布里珀罗腔的两侧各加一偏振镜 ,使两个偏振镜的起偏方向平行 ,并且偏振方向都相对于液晶分子长轴的方向成 45°角 ,入射光经多光束干涉后再经偏光干涉 ,导出其透射峰满足的条件为 2 (n∥ -n⊥)Lcosθ =mλ ,这样便克服了原有调谐滤光片两套光谱难以区分的缺点。对改进后的滤光片进行测试 ,在 15 5 0nm附近对该电调谐滤光片的滤光特性做了细致的分析

Study of Tunable Liquid Crystal Filter by Voltage

An improvement to the traditional Fabry-Perot tunable liquid crystal filter which makes liquid crystal as the intracavity dielectric layer is presented. Placing one polarizer on each side of the filter, and the angle between optical axis of the two paralleled polarizers and the molecular major axis of liquid crystal is 45°. The incident beam first generates multiple-beam interference, then polarized beam interference. It is concluded that the resonance wavelength is given by 2(n ∥-n ⊥)Lcosθ=mλ. So the disadvaisntage that the two spectra can′t be distinguished of the traditional Fabry-Perot tunable liquid crystal filter is overcomed. Near 1550 nm, the characteristics of this tunable filter is analysed under 1.6 V, 1.9 V, 2.3 V.