Patent ID: 7027129

Claim:
A multiplexer located in a beam conditioner in a lithography system, the multiplexer comprising: a mirror; and first and second spatially separated beam splitters positioned on a same side of and parallel to the mirror to expand a continuous beam of light emitted by a laser source into a plurality of continuous beams having light intensity substantially equal to each other without changing a spatial coherence of the light emitted by the laser, the beam being received by illumination optics in the lithography system, wherein a plane of the first beam splitter is located parallel to and a distance d from a plane extending from a reflecting surface of the mirror, wherein d=a/(2*sin α), a is a width of the light emitted by the laser source, L is a temporal coherence length of the light, and α is an illumination angle of the light with respect to the first beam splitter, wherein a plane of the second beam splitter is located parallel to and a distance 2d apart from the plane of the mirror, wherein an edge of the first beam splitter is laterally shifted a distance b with to respect to a section of the mirror, wherein b=d*tan α, and wherein an edge of the second beam splitter is laterally shifted a distance 2b with respect to the section of the mirror.