| 摘要 |
PURPOSE:To realize a laser oscillation with a stable oscillation wavelength by a method wherein a light intensity is detected at two or more points in a light beam dispersed by a disperser and the state of the dispersed light is varied in accordance with the output of a detection means of the light intensity. CONSTITUTION:A light beam emitted from a laser tube 1 is transmitted through an iris 7 and dispersion prisms 4 and 5, reflected by a movable mirror 2, transmitted again through the dispersion prisms 4 and 5, and reaches the iris 7 as a dispersed beam 6. The center part of the beam 6 is transmitted through the iris 7 and returns to the laser tube 1. The respective portions of the other part of the beam 6 are guided to photosensors 8 and 9 through the upper and lower apertures of the iris 7 and the intensities of those portions are detected and compared by a comparator 10. If the intensity detected by the photosensor 8 and the intensity detected by the photosensor 9 are different, a control signal is transmitted to a mirror driving apparatus 3 from the comparator 10 and the mirror driving appratus 3 drives and controls the inclination angle of the movable mirror 2 in accordance with the control signal so as to make the output of the photosensor 8 and the output of the photosensor 9 equal. |
