Patent ID: 6892013

Claim:
An optical system for reducing the coherence of a beam for illumination of an object, comprising: a source of at least partially coherent illumination, at least part of said illumination having a characteristic coherence length; a first fiber optics bundle comprising a plurality of optical fibers, at least some of which have differing optical lengths, at least some of said fibers of differing optical length having differences in optical lengths therebetween which are less than said characteristic coherence length; and at least a second fiber optics bundle disposed serially with said first bundle, comprising a plurality of groups of optical fibers, each group of fibers comprising fibers of essentially the same length, and wherein at least some of said group of fibers have differing optical lengths, at least some of said groups of fibers having differences in optical lengths therebetween which are at least equal to the sum of all of the optical length differences of said fibers in said first bundle.