Patent ID: 6801368
Filing Date: 2004-10-05
Classification: G02B,G03F

Abstract:
A method of transforming a beam of electromagnetic radiation, comprising:providing at least one optical element that includes a first and a second aspherical, non-planar, non-reentrant surface; directing an input optical beam of substantially non-uniform intensity onto the first surface, wherein the intensity profile of the input beam is expressible as a first function of a first coordinate times a second function of a second coordinate, the first and second coordinates being independent of each other, and wherein each of the surface has a sag value that is expressible as a sum of contributions that depend on the first and second coordinates, respectively; and transforming substantially all of the input beam into an output beam that propagates away from the second surface, said aspherical surfaces selected to perform said transforming, wherein the output beam includes a central region over which the optical intensity is substantially uniform, the central region including most of the optical power in the output beam, the intensity of the output beam outside the region varying gradually to substantially reduce diffraction effects.