An exposure apparatus includes a beam splitter for splitting light from a light source into first and second beams, a spatial light modulator, arranged in an optical path for the first beam, for modulating a phase distribution of the first beam, a beam coupler for coupling the first beam with the second...http://www.google.com/patents/US7239372?utm_source=gb-gplus-sharePatent US7239372 - Exposure apparatus and device manufacturing method
