Patent ID: 6392808
Filing Date: 2002-05-21
Classification: B23K,G02B,G03F,G03H,H04B

Abstract:
An optical system comprising an analog diffusing element formed by a plurality of regions having a pattern thereon, said pattern being formed by smooth, free form shaped analog features:the majority of the analog features having a phase depth of greater than 2&pgr; at a nominal design wavelength, whereby the efficiency of zero order light passed by the element is relatively insensitive to wavelength; the analog features having respective slopes defined by their respective phase depths and feature widths, said slopes determining the angular spread of light deflected by said features; the relative population of said analog features having a given slope determining the fraction of incident light deflected within a corresponding angular spread; wherein each of said plurality of regions, when illuminated by a same input beam, transmits a beam with a predetermined angular spread, so that a given angular spread is imparted to the input beam, wherein the angular spread of the output beam is relatively insensitive to spatial energy distributions within the incident beam, and wherein, within each region, the analog features provide a non-random distribution of slopes statistically corresponding with the given angular spread.