可调谐液晶滤波器的调谐性能研究

在电调谐液晶法布里一珀罗腔滤波器的连续调谐过程中，存在“透射峰跳跃”现象，影响器件的单调调谐性。为了改善器件的单调调谐性能，对此现象进行了分析，表明这是由于法布里—珀罗腔干涉级次在调谐过程中发生改变引起的；进而给出了法布里一珀罗腔透射波长λ，干涉级次m与腔内介质折射率n的关系，以及器件实际的有效调谐范围。当腔长为10μm、折射率差为0．05时，就可以使器件的单调调谐范围达到整个C波段。数值模拟与实验结果相吻合。并针对改善器件的单调调谐性能，提出了几种可行的方案。

Study of the Tuning Performance of Tunable Liquid Crystal Filter

In the continuous tuning process of the electric tunable liquid crystal Fabry-Perot filter (LCFPF), the phenomenon of the jumping of the transmission peak spectrums is found. And this phenomenon influences the monotone tuning performance of the device. Analysis for this phenomenon shows that it's due to the change of the interference order of Fabry-Perot cavity in the tuning process. And the relationship between the transmission peak wavelength λ, the interference order m, and the index n of the medium in the Fabry-Perot cavity is given, as well as the effective tuning range of the device. When the length of the cavity is 10 μm, the tuning range will cover the whole C Band with the index difference of only 0.05. The experimental result is in agreement with the numeric simulation. At last, some approaches are presented in order to improve the monotone tuning performance of the device.