光学支架是太赫兹(THz)实验系统的重要组成部分，通过研究一些常用的光学支架对THz光的反射特性，并以此为依据采取合理的措施降低反射影响，对提高实验精度具有重要意义。对一些常用的光学支架，如方形滤波片固定座、三角块、不锈钢接杆和杆座等，进行了反射率测量实验，采用对比测量法，通过计算获得了不同支架在45°入射角时对2.52 THz光的近似反射率。实验结果表明，光滑的不锈钢接杆反射率较大，实验测得直径为25 mm的不锈钢接杆的反射率最高可达约43%；表面不平整的直径为25 mm的喷漆杆座的反射率较低，为0.62%；而表面有菱形条纹的直径为28 mm的升降杆座的反射率仅为0.35%。

Optical brackets are important parts of a terahertz (THz) experiment system. It is of great significance to improve the experimental accuracy by studying the reflection properties of the common optical brackets and taking proper measures to reduce reflection impacts. In this paper, a variety of common optical brackets, such as a square filter fixed bracket, a triangle block, two stainless steel connected rods and several rod bases et al., are measured in the reflection experiments by using contrast measurement method. The reflectivity of the optical brackets with incident angles of 45° using 2.52 THz laser have been obtained approximately. It can be inferred from the results that the smooth stainless steel connecting rods have a relatively higher reflectivity. The reflectivity of the rod with a diameter of 25 mm is about 43%. For the painting rod base with uneven surface and a diameter of 25 mm, the reflectivity is 0.62%. The reflectivity of the diamond-shaped stripe area of the lift rod base is only 0.35%.