Patent ID: 6628682
Filing Date: 2003-09-30
Classification: H01S

Abstract:
A wavelength detection device used in a line-narrowed laser apparatus which outputs a narrowed oscillation line that has been amplified and narrowed and which includes a laser chamber for generating spontaneous emission beams by discharging and exciting a laser medium accommodated in the laser chamber; a resonator for amplifying the spontaneous emission beams by moving the spontaneous emission beams back and forth on a path that sandwiches the laser chamber; and a line narrowing element, disposed on the path, for narrowing the spontaneous emission beams by transmitting therethrough or reflecting thereat the spontaneous emission beams to thereby narrow a line width and select a wavelength, the wavelength detection device being arranged for detecting, on the basis of a wavelength of a reference light, a wavelength of the narrowed oscillation line, wherein:of the spontaneous emission beams generated by the laser chamber, a spontaneous emission beam whose wavelength approximates the narrowed oscillation line and whose light intensity is a certain level or higher, is taken out of the path without being transmitted through or reflected at the line narrowing element and used as a reference light.