The laser device null YLF laser illuminant for exposure which uses

摘要

PROBLEM TO BE SOLVED: To provide a light exposure laser device which is capable of making a gas laser source which emits light of wavelength 190 nm or below emit laser rays which are easily stabilized in wavelength and lessened in band width. SOLUTION: A coherent light source 1 is composed of a laser ray source which oscillates laser pulses whose oscillation frequencies are narrow in band width, a nonlinear optical crystal for obtaining the higher harmonics or light of sum frequency of the output light of the laser source, and a wavelength conversion means which uses an induction Raman effect, light emitted from the coherent light source 1 is stabilized in wavelength by a wavelength stabilizing means 3, and a seed light nearly equal in wavelength to laser rays emitted from the gas laser source 2 is emitted from the wavelength stabilizing means 3. The seed light is synchronously injected into the gas laser source 2 composed of a F2 laser or the like, and the gas laser source 2 emits light pulses which are 190 nm or below in wavelength. The rise timing of light pulses emitted from the coherent light source 1 and the rise timing of oscillation pulses of the gas laser source 2 are controlled by a timing control means 4.