Translation-tolerant mask matching using noncoherent reflective optics

Abstract A general difficulty with two-dimensional optical mask matching is the need for accurate registration of the input pattern with each of the masks of the pattern set. A technique is described in which we are able to trade some of the potential performance of a pure two-dimensional correlator for the achievement of registration tolerance. We have, in other words, a modified two-dimensional cross-correlation scheme that offers a significant degree of translation tolerance. Results from a few experiments that verify the basic technique are presented.