Experimental determination of lens aberrations from the intensity point-spread function in the focal region

In this paper we show various results of aberration retrieval using the pinhole method in conjunction with the extended Nijboer-Zernike theory. The experiments are performed on modern wafer scanners. Keyboard commanded offsets of the movable lens elements of the imaging tool have been used to introduce astigmatism, coma and spherical aberration in a controlled way. The method is designed to estimate these induced aberrations and we show the experimental results regarding the various types of aberrations created this way