Illumination of objects for speckle-pattern shearing interferometry by illuminating from several directions to give overlapping regions to match contour of object under test

摘要

One or more coherent radiation sources illuminate the object surface simultaneously from several directions. The illuminated sub-regions of the object section under test can selectively completely intersect each other and overlap, so that the illumination or intensity can be matched specifically to the contour of the object. An illumination apparatus is also claimed.