设计了一种基于铌酸锂晶体的电控可调谐波导光栅双波长滤波器。在可同时传输横电波(TE)和横磁波(TM)模式的钛扩散波导上刻写布拉格光栅，能够实现正交偏振的双波长滤波。利用铌酸锂的电光效应改变波导的有效折射率，可以实现两个布拉格波长的快速调谐。对波导光栅滤波性能的分析结果表明，蚀刻光栅在蚀刻坡度小于15°，蚀刻占空比为1/2 时，滤波特性最好，且随着蚀刻深度的增加，光栅的反射率与带宽均增加。通过横向电场对波导光栅进行调谐，双波长滤波器的TE 模式调谐灵敏度达到15.6 pm/V，TM 模式的达到5.5 pm/V。

An electrically controlled double wavelength tunable filter based on lithium niobate (LN) is designed. Double wavelength of orthogonal polarization filter is achieved by etching Bragg grating on the Ti-diffusion LN waveguide, which supports transverse electric (TE) mode and transverse magnetic (TM) mode. The refractive index distribution and therefore the Bragg wavelength can be fast tuned by using electro-optic effect in LN. The performance of waveguide grating filter is analyzed and results show that the grating with 1/2 etching duty cycle and less than 15°etching angle has the best filter characteristic. The reflectivity and bandwidth increase with the etching depth increasing. Double wavelength filter achieves 15.6 pm/V sensitivity for TE mode, 5.5 pm/V sensitivity for TM mode by adding the transverse electric field on waveguide grating.