정현파 회절격자를 이용한 비구면렌즈의 파면수차 측정

A improved method to measure the wavefront aberration of aspheric lens is described. In this study, which is a kind of lateral shearing interferometry, a sinusoidal diffraction grating is used for better quality of interferogram. Also,the grating is inclined to horizontal axis for obtaining the two orthogonal derivatives and minimizing moving error simultaneously. Measurement result shows that the repeatability is about 6 times better then that of previouse Ronchi Test.