基于液晶分子的双折射特性,设计并制作了一种结构简单的可用于波分复用系统中的可调谐液晶法布里珀罗滤光片。对器件的光谱调谐特性进行了分析和模拟,并得到了液晶分子的折射率调制与其分子在电场作用下产生的转动角度之间的关系式。最后,对所设计的结构进行了制作和实验,测试结果显示了滤光片的性能受液晶分子的排列特性和法布里珀罗腔的反射镜参量的影响较大,同时实验表明了这种利用向列型液晶分子作为法布里珀罗腔内介质的可调谐滤光片在加电压调试下其调谐性能良好,调谐范围可覆盖C波段,透过峰的半峰全宽达到了0.8 nm,实验结果与设计相吻合。

Based on the birefringent effect of liquid crystal, a liquid crystal Fabry-Perot filter in simple structure is designed and fabricated. This device can be used in wavelength division multiplexing. The tunable characteristic of this device was analyzed and simulated; the formula of the relation between the liquid crystal refractive index modulation and the rotary angle of the liquid crystal molecule arose from the modulated voltage is got. The test of the fabricated tunable filter shows that the performance of the device is mainly affected by the alignment of the liquid crystal molecule and the parameter of the reflectors of the Fabry-Perot cavity, and the tunable characteristic is good for this kind of device with the nematic liquid crystal as the media in the Fabry-Perot cavity. The tunable range of the tunable filter covers the C band and the full width at half maximum (FWHM) could reach 0.8 nm, the experimental result was coincident with the design well.