| 摘要 |
<p>An optical device, an exposure system, and a laser beam source capable of suppressing a hazing from occurring on an optical element while a working environment in maintenance and at the time of abnormality is maintained in good condition, wherein an inert gas feed system (33) and a dry air feed system (35) are connected selectively to a first lens-barrel (46) and a second lens-barrel (48) of an exposure device main body (11) and a light source chamber (16) of a laser device (12), oxygen sensors (78, 42) for measuring the oxygen concentration and exhaust amount monitors (77, 41) for detecting the exhaust amount through an exhaust duct (40) are provided inside a chamber (45) of the exposure device main body (11) and a chamber (15) of the laser device (12), respectively and, when at least one of the oxygen concentration and exhaust amount detected by the oxygen sensors (78, 42) and exhaust amount monitors (77, 41) lowers below a specified value, a purge gas fed to the first and second lens-barrels (45, 46) and light source chamber (16) is switched from inert gas to dry air.</p> |
