NARROW BAND OSCILLATION EXCIMER LASER CONTROL DEVICE

摘要

PURPOSE:To enable an excimer laser to be quickly controlled in power and to be improved in controllability of power by a method wherein an etalon and grating are provided together in an optical resonator, and the selection center wavelength is intermittently shifted so as to overlap the selection center wavelength of the etalon at overlapping control. CONSTITUTION:The center wavelength lambda and the center wavelength power P1 of a sample light detected by an oscillation center wavelength and center wavelength power detector 301 are inputted into a central processing unit (CPU) 302 which constitutes a wavelength controller. The CPU 302 shifts an etalon 101 in passing light center wavelength (selection light center wavelength) controlling the etalon 101 in angle or the like so as to set an output light or a sample light detected by the detector 301 to a required value in wavelength. An overlapping control is carried out in such a manner that the selection light center wavelength of a grating 106 is made to shift by a prescribed unit wavelength at a time so as to make the center wavelength power P1 detected by the detector 301 maximal enabling the selection center wavelengths of the etalon 101 and the grating 106 to overlap each other. Therefore, an excimer laser of this design is sharply improved in power controllability.