A one-port reflector for transverse-electric (TE) polarization and a two-port beam splitter for transverse-magnetic (TM) polarization is proposed by T-type double-layer fused-silica grating. After optimization calculations, 97.87% single-order high-efficiency reflection under TE polarization and 48.70%/48.71% highly uniform dual-order beam splitting under TM polarization are finally obtained. In addition, the normalized electric field and magnetic field diagrams of the grating are obtained using the finite element method. Finally, the incident characteristics and process tolerances of the grating are analyzed, and a range of structural parameters that meets good reflection efficiency is found. The design and study of polarization-dependent gratings carried out in this paper are of great significance for increasing the output power of laser systems and improving the stability of optical devices when unpolarized lasers are incident.

通过T型双层熔融石英光栅提出了一种用于横向电（TE）偏振的单端口反射器和用于横向磁（TM）偏振的双端口分束器。经过优化计算，最终得到TE偏振下97.87%的单阶高效反射和TM偏振下48.70%/48.71%的高均匀双级分束。此外，光栅的归一化电场和磁场图是使用有限元方法获得的。最后，分析了光栅的入射特性和工艺公差，找到了一系列满足良好反射效率的结构参数。