Abstract

The derivative of an object can be obtained by subtracting two linearly shifted versions of the object, and the linear shift can be obtained by shifting the optical center of a lens. In this work, we use a computer program to form an optical element by subtracting two Fresnel lenses having different optical centers. The two images that are formed subtract in areas where they overlap so that only the edges remain. This optical element is then written onto a magneto-optic spatial light modulator (MOSLM), which permits programmable differentiation of the image. The spatial direction of the image differentiation can be varied by changing the direction in which the two lenses are shifted. Results showing the differentiation operations of d/dx, d/dy, and d²/dxdy are presented.

© 1990 Optical Society of America