| 摘要 |
PURPOSE:To enable to easily change over the beam radius of a gas laser at need by a method wherein the reflector on the output side is constituted of a mount, whereon a plural number of reflectors having a different curvature respectively have been installed, and a mechanism, which selects a mirror having an arbitrary curvature among the different curvatures and change over the beam radius, is provided. CONSTITUTION:Concave mirror 1-4, which are reflectors on the output side, are fixed by a gimbal 7 and a plane mirror, which is a reflector on the total reflection side, is fixed by a gimbal 6. The optical resonator of the titled gas laser is constituted of the concave mirrors 1-4 and the plane mirror on the total reflection side. As the length of the resonator is constant, the beam radius is decided by some of the curvatures of the concave mirrors 1-4. Accordingly, by rotating the gimbal 7 to the laser optical axis, the concave mirrors are easily varied extending from 1 to 4 and a respective optical resonator according to the variation is constituted. As a result, the beam radius can be changed according to the curvature of an arbitrary mirror among the concave mirrors, and moreover, the diffraction loss can be also changed. |
