| 摘要 |
PURPOSE:To lessen an etalon in frequency of replacement and to enable an excimer laser to be improved in operating efficiency and lessened in running cost by a method wherein a means which enables the etalon to move rotationally and two-dimensionally on a plane parallel to its optical plane is provided. CONSTITUTION:An etalon 4 is disc-shaped, an etalon holder 401 which fixes the etalon 4 is ring-shaped and supported at a horizontally movable table 403 through the intermediary of a roller 402. The etalon 4 and the etalon holder 401 are rotatable to the horizontally movable table 403, the horizontally movable table 403 is supported with screws 405 so as to be movable in a horizontal direction on a vertically movable table 404, and the vertically movable table 404 is supported with screws 406 so as to be movable in a vertical direction on a base plate 407. Therefore, the etalon is able to rotate and move two- dimensionally on a plane vertical to the optical axis of a laser beam parallel to its optical plane. Therefore, a part of the etalon 4 where the laser beam passes can be optionally selected to change. By this setup, an etalon can be lessened in frequency of replacement, and an excimer laser can be improved in operating efficiency and lessened in running cost. |
