In this paper, a simple and practical method is proposed. The fringe patterns are generated on a computer display (for example, a LCD or TFT monitor) and the images refracted via the tested optical component are recorded by a CCD camera. The intensity patterns in these images are distorted because of the tested object. Using the well-known phase-shifting algorithms, the alterant phase caused by the tested object can be precisely obtained. And the aberration of each refracted ray with the reference sphere can be obtained by use of geometry principle. Then the wave front aberration is restored with Zernike polynomial fitting algorithm according to the relation between wave aberration and ray aberration. The technique allows the measurement for high aberrated wave fronts, owing to its ability to measure large ray slope changes, and the use of a computer display generation leads flexible adjustment of period and direction of patterns and accurate phase shift. Compared with other techniques, this technique is simpler, cheaper and more flexible.

Date Published: 20 May 2009
PDF: 4 pages
Proc. SPIE 7283, 4th International Symposium on Advanced Optical Manufacturing and Testing Technologies: Optical Test and Measurement Technology and Equipment, 728320 (20 May 2009); doi: 10.1117/12.828692

Published in SPIE Proceedings Vol. 7283:
4th International Symposium on Advanced Optical Manufacturing and Testing Technologies: Optical Test and Measurement Technology and Equipment
Yudong Zhang; James C. Wyant; Robert A. Smythe; Hexin Wang, Editor(s)