大口径球面反射镜曲率半径的精确测量

介绍了大口径球面反射镜曲率半径的传统测量方法，提出了利用组合测杆结合激光干涉仪测量球面反射镜曲率半径的新方法。首先利用激光干涉仪检测球面反射镜的面型，调整干涉仪与被测镜的位置，使被测镜达到零条纹干涉状态，然后架设合理长度组合测杆，调整组合测杆靠近干涉仪端测量球头的位置，使之达到零条纹干涉状态，再使组合测杆另一端测头与镜面接触完成测量，通过计算分析即可得到被测球面镜的曲率半径。对该方法的基本测量原理进行了研究分析，并对口径为600 mm的望远镜球面主镜的曲率半径进行了多次测量，测得其曲率半径均值为2 836.774 mm，标准偏差为0.071 mm。最后对该方法的测量不确定度进行了分析，找出了影响测量精度的主要因素，合成标准不确定度为0.061 mm。

Precise measurement of curvature radius for spherical mirror with large aperture

Conventional testing methods for the curvature radius of spherical mirror with large aperture are in-troduced briefly , and a novel method using combined rods and laser interferometer is proposed .Firstly, the surface figure of spherical mirror is tested with laser interferometer .The position of interferometer and tested mirror is adjusted to make the focus of the exit wave front and the center of curvature of tested mirror to be confocal .Then the suitable combined rods are setup , and the position of probe spheric head which is close to interferometer is adjusted to make the focus of the exit wave front and the center of the probe spheric head con -focal.Next, another probe spheric head is adjusted to contact the surface of the tested mirror .The curvature radius of the spheric mirror can be calculated by the data .The basic principle of the testing method is ana-lyzed.A telescope spheric primary mirror with a aperture of 600 mm is tested many times with this method . The average radius of curvature is calculated to be 2 836.774 mm,and the root mean square is 0.071 mm.Fi-nally , the measurement uncertainty of this method is analyzed , and the main factors affecting the measurement accuracy are found out , and the composed standard uncertainty is 0.061 mm.