Patent ID: 6778584
Filing Date: 2004-08-17
Classification: G03F,H01S

Abstract:
A grating based line narrowing device for line narrowing a laser producing high energy laser said device comprising:(A) a grating defining a grating face, (B) a chamber for housing at least said grating, (C) a helium source for providing a helium purge for purging said chamber, (D) a beam expanding for expanding a beam from said laser to produce an expanded beam, (E) a tuning means for directing said expanded beam onto the grating face in order to select form said expanded beam a desired range of wavelength, wherein said expanded beam heats said grating face producing a temperature increase in said grating face which in turn heats the helium purge gas in a hot purge gas layer adjacent to said grating face, and further comprising a purged gas manifold for directing helium purge gas across the grating face to remove said purge gas layer to reduce optical distortion caused by said hot purge gas layer.