基于相移电子莫尔条纹的深度非球面检测

通过相移技术检测深度非球面波前时,CCD相机和计算机分辨率受到Nyguist频率的限制.基于相互平行相移莫尔条纹干涉技术,我们提出一种新颖有效的检测技术.相互平行的相移电子莫尔条纹是由计算机产生三幅光栅作为参考波前,分别和输入被检干涉图相叠加,并通过低通滤波器滤波滤掉高频而得到的.最后,由三步相移算法,我们得出非球面的面形分布.

Deep aspheric testing based on phase-shift electronic Moiré patterns

The resolutions of CCD camera and digital computer are limited by Nyquist frequency when deep aspheric wavefronts are tested using phase shifting technique. A new powerful technique based on parallel generations of three phase shift patterns through electronic multiplication with computer generated graftings and low pass filtering, is proposed for measuring wavefronts with large departures from a reference sphere such as those encountered during testing of steep aspheric surfaces. The phase distribution of aspheric surfaces is obtained using a three step phase shifting algorithm.