| 摘要 |
PURPOSE:To obtain an etalon excellent in surface irregularity and small in thermal strain by a method wherein solid members are provided to cover one or both sides of each reflective surface, where the objective light rays are capable to pass through the solid members. CONSTITUTION:Objective light ray transmissive solid members 4 and 5 are provided to both sides of reflective faces 2 and 3 sandwiching the surfaces 2 and 3 in between them or only the solid member 4 is provided to the reflective surface 2. In result, the heat input condition of an etalon due to laser rays hardly changes, and on the other hand, the curvature radius due to a thermal strain increases proportionally to the thickness and a thermal strain becomes small, and as the reflective surfaces 2 and 3 are covered with the solid members 4 and 5, the etalon is increased in rigidity. By these processes, the etalon excellent in surface irregularity and thermal strain resistance can be obtained. |
