Patent ID: 7653112

Claim:
A line narrowing module for a narrow band DUV high power high repetition rate gas discharge laser producing output laser light pulse beam pulses in bursts of pulses, the module having a nominal optical path, comprising: a dispersive center wavelength selection optic moveably mounted within an optical path of the line narrowing module, selecting at least one center wavelength for each pulse determined at least in part by the angle of incidence of the laser light pulse beam containing the respective pulse on the dispersive wavelength selection optic along a first elongated longitudinally extending dispersive surface of the dispersive center wavelength selection optic, extending in a first direction; a translation mechanism translating the dispersive center wavelength selection optic in a second direction generally orthogonal to the first direction sufficiently to expose a second unused elongated longitudinally extending dispersive surface of the dispersive center wavelength selection optic to the laser light pulse beam.