基于几何光学理论和矢量衍射理论，设计了263 GHz DNP-NMR谱仪的改进反射镜系统，并进行了数值模拟.该系统包括两个波纹波导、一个抛物面镜和一个角度可调的相位校正镜.仿真结果表明，获得了聚焦良好的类高斯输出光束，其标量高斯模含量为99.90%，矢量高斯模含量为99.55%.只有通过调整相位校正镜的角度来匹配DNP-NMR样品，才能改变输出光束的方向.当输出光束方向在±15^o变化时，标量高斯模含量约为99.57%，矢量高斯模含量约为98.97%.

The improved transmission and mirror system for a 263 GHz DNP-NMR spectrometer has been designed and numerically simulated based on the geometric optics theory and the vector diffraction theory. The system includes two corrugated waveguides, a parabolic mirror and an angle-adjustable phase-correcting mirror. The simulation results show that a well-focused Gaussian-like output wave-beam with 99.90% scalar Gaussian mode content, 99.55% vector Gaussian mode content has been obtained. The direction of the output beam can be changed by only adjusting the angle of the phase-correcting mirror to match the DNP-NMR sample. The scalar Gaussian mode content is about 99.57%, and the vector Gaussian mode content is about 98.97% when the direction of the output beam changes in ± 15^o.