Patent ID: 9477025
Filing Date: 2016-10-25
CPC Classification: G02B,G03F,G21K,H05G

Claim Text:
1. A light source, comprising: a generation device configured to generate a first EUV beam having a polarization that is a superimposition of two linearly polarized waves with directions of polarization that are perpendicular to each other and that have a phase difference with respect to each other that is non-zero and not an integral multiple of π; and a polarization setting device configured to interact with the first EUV beam to provide a second EUV beam by exerting an effect on the first EUV beam that is linearly polarizing with respect to the direction of polarization to set a polarization of the second EUV beam, wherein the polarization setting device comprises a phase retarding component in a beam path of the first EUV beam, and the polarization setting device is configured to exert a phase shifting effect on the two linearly polarized waves of the first EUV beam, and wherein the phase retarding component comprises a plurality of reflective phase retarding components configured to reflect the same partial beam of the first EUV beam.