| 摘要 |
PURPOSE:To avoid the thermal deformation of window and thermal lens effect by a method wherein laser beams are magnified within an oscillator before passing window. CONSTITUTION:The laser beams emitting from a perforated mirror 6 of an unstable oscillator are led into a window 3 through a beam magnifying mirror 10, a bending mirror 11. The thermal lens effect due to laser beam absorption into the window 3 may be eliminated since the power density of laser beams is reduced by the beams magnified by the mirror 10 also the change of diameter of the beams 2b after passing the window 3 due to laser output and the uneven distribution of the beam intensity is eliminated. The beams 2b may be focussed by convex lens window 3 to be led into the atmosphere as parallel beams 2c with proper diameter corrected by correcting mirror 12 to be transferred to a processing lens 7 through a transfer mirror 13. |
