Patent ID: 7598508
Filing Date: 2009-10-06
Classification: B82Y,G02B,G03F,G21K

Abstract:
1. In a system that receives a beam of light from a source and delivers the beam to a downstream optical system, a gaseous spectral-purity filter (SPF) through which the beam from the source passes as the beam propagates to the optical system, the gaseous SPF being formulated and configured to enrich the beam in at least one desired wavelength as the beam passes through the gaseous SPF; the source and optical system being situated in a subatmospheric-pressure environment; the gaseous SPF being configured as a stream of SPF gas flowing in the subatmospheric-pressure environment; and the gaseous SPF further comprising a stream of sheath gas enveloping the stream of SPF gas such that the beam passes through both streams as the beam passes through the gaseous SPF.