How to extend the light emitted from the laser beam without changing spatial coherence of the light emitted by the laser light projection system, and an optical multiplexer

摘要

An system and method that expand emitted light from a laser beam without changing spatial coherence or producing speckle. The system includes a laser source and an optical projection system having a multiplexing device. The multiplexing device expands light emitted by laser source into plural beams having light intensity about equal to each other without changing spatial coherence. The multiplexing device has a plurality of spatially separated beam splitters positioned parallel to and on a same side of a mirror. The system further includes an illuminating optical system that focuses each of the plural beams and a projection optical system that projects an image of a mask illuminated with light output from illuminating optical system onto a substrate. IMAGE