| 摘要 |
PURPOSE:To obtain constant laser-condensing performance and further fixed processing performance by a simple beam transmission system without unnecessarily enlarging a mirror for transmission and a condenser lens by using an optical material having small thermal strain and previously processing a window to a convex lens shape so as to compensate an angle of divergence of a laser. CONSTITUTION:Doughnut mode laser beams extracted from an unstable type laser resonator are deflected by a total reflection plate mirror 3, and extracted outside an oscillator 1 through a laser-beam extracting window 5. Laser beams are refracted by the window 5 previously processed to a convex lens shape, and oscillator-output beams are made approximately parallel. KCl, etc. are used as the principal ingredients as the quality of materials of the window 5, and the form and refractive index of the window hardly change even to large-output beam transmission for a prolonged time, and the focal distance of the window is set in such a manner that beams are extracted by a parallel plate window having the same quality of materials, the angle of divergence of beams is measured and a value compensating the angle is calculated. Accordingly, approximately parallel beams can be taken out of the laser oscillator, thus simplifying a transmission system, then stabilizing processing. |
