一种采用光学比较测角仪测量碲化镉晶体平行度的方法

对碲化镉晶体进行了光学加工,利用两台测量精度为1″的光学比较测角仪和一块平行度优于1″的平行平晶测量了其平行度,并且和光学加工过程中采用激光平面干涉仪测得的氟化钙陪片的平行度进行了比较,分析了这种测量方法的误差来源及大小.结果表明:采用此方法测得的碲化镉晶体的平行度和采用激光平面干涉仪测得的陪片的平行度相差不超过3″;此方法的误差主要来自于光学比较测角仪的测量误差和平行平晶的平行度误差,总误差最大不超过5″,能够满足碲化镉晶体平行度测试的精度要求.

A Method to Measure Parallelism of CdTe Crystal Using Precision Goniometer

The CdTe crystals were processed optically and the parallelism was measured by using two precision goniometers with measurement accuracy of 1″ and a optical flat with parallelism better than 1″, the measured parallelism was compared with that of CaF2 crystal which was processed together with CdTe crystals.The parallelism of CaF2 crystal was measured by a laser plane interferometer.Additionally, the source and magnitude of error in this method were analyzed.The results show that the difference of the parallelism of CdTe and CaF2 is less than 3″.The error mainly come from the measurement error of precision goniometer and the parallelism error of optical flat, and the total error is no more than 5″,which can meet the precision require of parallelism measurement for CdTe crystal.