| 摘要 |
PURPOSE:To arrange optical elements in clean environments so as to elongate their service lives by respectively surrounding an optical element used as a laser resonator and another optical element used as an output laser beam detector with enclosure means and providing a purging means which purges the insides of enclosures with a clean gas. CONSTITUTION:The title device is provided with enclosure means 7 and 20 which respectively surround an optical element used as a laser resonator and another optical element used as an output laser beam detector and a purging means 24 for purging the insides of enclosures 15 and 22 with a clean gas. In addition, in order to make the surfaces of the enclosures 15 and 22 and optical element holders stable against an excimer laser beam, aluminum is used for manufacturing the enclosures 15 and 22 and holders of various kinds of optical elements and white anodic oxidation is performed on their surfaces by using an inorganic pigment. Therefore, the service lives of the optical elements are elongated, because the amounts of dust and harmful chemical substances are reduced from the periphery of the optical elements. |
