在考虑液晶(LC)双折射效应和旋光效应的基础上,探究了不同预倾角和扭曲角下向列相LC滤波片的输出特性,导出了其透射率表达式,并用Matlab软件对其进行了数值模拟分析和实验测试。结果表明,随着扭曲角的增大,LC滤波片的透射峰值向长波方向移动;随着预倾角的增大,LC滤波片的透射峰值向短波方向移动且其移动速率随波长变化,波长越短移动速率越小;若增大下基板预倾角,减小上基板预倾角(或者减小下基板预倾角,增大上基板预倾角)则其透射峰值向短波方向的移动速率会减弱;当下基板预倾角的增量值与上基板预倾角的减量值(或者下基板预倾角的减量值与上基板预倾角的增量值)之比约为1.2时,其透射峰的中心波长将不会发生漂移。通过实验,进一步验证了理论结果的正确性。
In order to research the effects of pretilt and twisted angles on the nematic liquid crystal(LC)filter,based on the birefringence and distortion effects,the nematic LC filter has been analyzed through the deductive theory and simulated by MATLAB software.And its transmittance expression also has been derived from the optical theory.The further experiments indicate that the transmittance is associated with the pretilt angle and twisted angle.If the twisted angle is increased,the transmittance peak of the nematic liquid crystal filter will shift to long wavelength.With the increase of the pretilt angle,the liquid crystal filter transmission peak moves to the short wavelength and the peak′s shift rate is related to the wavelength-the shorter the wavelength slower,the shift rate the pretilt angle of the bottom glass substrate is increased and that of the top glass substrate is reduced(or the pretilt angle of the bottom glass substrate is reduced and the top glass substrate is increased),the rate of transmittance peak moving to shorter wavelength will weaken;and when the ratio of the incremental value of the pretilt angle on the bottom glass substrate to the reductional value of the pretilt angle of the top glass substrate(or the ratio of the reductional value of the pretilt angle on the bottom glass substrate to the incremental value of the pretilt angle of the top glass substrate)is about 1.2,the center of the transmission peak will not drift.