Patent ID: 7538948

Claim:
An optical system to create from an incident beam of light an intensity distribution on a surface of a substrate, the optical system comprises: at least a first optical element which splits the incident beam into a plurality of beams some of which at least partially overlap in a first direction on said substrate surface; and at least a second optical element positioned to receive the plurality of beams of light from the first optical element and direct the plurality of beams towards said substrate surface, wherein the second optical element introduces angular differences between directions of at least a first and a second of said plurality of beams, where the angular differences displace at least part of the first beam with respect to the second beam in a second direction on said substrate surface, the second direction being essentially perpendicular to the first direction, the intensity distribution continuously extends over an area on the surface of the substrate having a dimension that is greater than 100 mm in the first direction and a dimension that is smaller than 100 μm in the second direction, where said first optical element comprises two arrays of sub-elements and said two arrays are arranged displaced along an optical axis and said second optical element is arranged between said two arrays.