干涉仪测量球面曲率半径的精度分析  

Precision analysis of measurement of radius of curvature by interferometer

作　　者：王青[1] 徐新华[1] 

机构地区：[1]南京理工大学电子工程与光电技术学院,南京210094

出　　处：《东南大学学报（自然科学版）》2009年第S2期55-59,共5页Journal of Southeast University：Natural Science Edition

摘　　要：利用数字波面干涉仪对光学球面曲率半径进行直接测量和间接测量,分析了2种测量方法的误差来源及测量精度,给出了方法的适用范围和局限性.结果表明,基于光栅尺的直接测量方法的精度受限于齐焦位置与猫眼位置的判读精度,其测量不确定度在10~70μm的范围内,与f数相关并与球径仪的测量精度相当;利用平面干涉仪测量球面波矢高后间接计算曲率半径的方法适合f数大于1 000的长曲率半径的测量,其精度为0.8~0.3m,与干涉仪的标准平晶平面度和测试稳定性密切相关.通过提高标准平晶的平面度和控制测量环境,针对口径6mm、曲率半径9m的激光陀螺反射镜进行的曲率半径测量精度达到0.05m,与ZYGO NewView7 000 3D型表面轮廓仪的测试结果差异为0.03m.The radius of curvature(ROC) is measured by direct and indirect measurement methods using a digital wavefront interferometer.The error sources and measurement precisions of the two methods are discussed by the error analysis theory.The applicative scopes and limitations are also presented.The results show that the accuracy of the direct measurement method using grating scale depends on the certainty of the confocal position and the cat's eye position.The measurement uncertainty of the method is between 10 to 70 μm,which is related to the f-number and equivalent to the measurement uncertainty of a spherometer.The indirect measurement method by testing the bow height of aspherical wavefront using an interferometer is suitable for the specimens with the f-number of greater than 1000.Its accuracy is between 0.8 to 0.3m,depending on the flatness of the interferometer's reference flat and the stability of the test.By improving the quality of the interferometer's reference flat and controlling the testing environment,the accuracy of the ROC measurement is 0.05m for the laser gyroscope mirror with the diameter of 6mm and the ROC of 9m.The difference between the result and that obtained by a ZYGO NewView 7000 3D optical surface profilometer is 0.03m.

关 键 词：曲率半径 干涉仪 误差分析 

分 类 号：TH744.3[机械工程—光学工程]