用虚光栅移相莫尔条纹法测量小球面曲率半径

Measurement of the curvature radius of a small spherical surface with virtual grating phase-shift Moir fringe method

随着近代光学、光通信等领域的迅猛发展,光学元器件的微小化已成为一个重要的发展趋势。球面是微小光学元件常见的一种面形。研究了一种基于虚光栅移相莫尔条纹术测量小球面曲率半径的方法。实验以Askania环形球径仪配备的曲率半径为17.92mm的标准凸球面样板为例,利用干涉显微镜拍摄了一幅含有载频的被测球面非接触干涉图,通过运用4幅虚光栅、图像相乘、频域滤波和四步移相等算法得到了被测球面的曲率半径。测量均值为R=17.97mm。实验结果表明:用虚光栅移相莫尔条纹法测量小球面曲率半径是完全可行的。

With the rapid development in modern optics, optical communications, etc. , the miniaturization of optical components has become an important trend. Spherical surfaces are a kind of common profile. Virtual grating phase-shift Moire fringe method is adopted to measure the curvature radius of a standard small spherical template with nominal value of 17. 92mm, equipped for an Askania spherometer. With an interference microscope, a spherical untouched carrier interferogram is taken. By utilizing 4 virtual gratings, image multiplication, frequency- domain filtering, and 4-step phase-shift algorithm, etc., the radius result, 17. 97mm, is obtained. The experimental results show that virtual grating phase-shift Moire fringe method is entirely practicable for measuring the radius of a small spherical surface.