Patent ID: 7751461
Filing Date: 2010-07-06
Classification: H01S

Abstract:
1. A line-narrowed excimer laser system comprising: a laser cavity comprising a gain medium, an output coupler and a reflector assembly, the reflector assembly comprising at least two sequentially arranged grating-prisms (grisms), each grism having an input surface and an output surface, and a wavelength-selective diffraction grating arranged in sequence, with a first of the at least two grisms having a first grating disposed on the input surface of the first grism and facing the gain medium, with the first grating operating in 2 wherein the wavelength-selective diffraction grating operates in Littrow configuration and diffracts the received expanded diffracted beam back through the at least two grisms into the laser cavity, thereby narrowing the linewidth of the laser emission wavelength relative to the wavelength distribution of the laser light produced in the gain medium.