| 摘要 |
PURPOSE:To maintain the stable output of a laser beam for many hours by a method wherein the output of the laser beam is detected, a rare gas is supplemented on the basis of a detected value and the output is restored. CONSTITUTION:The intensity of a laser beam L is detected by using a photosensor 16. When the output of the detected laser beam L becomes lower than a set value which has been set in a comparator 17, a comparison signal is output to a computing device 18 from the comparator 17, and a driving signal is output to a control valve 14 from the computing device 18. The control valve 14 is opened by the driving signal for a prescribed time; a rare gas is supplied to a laser tube 1 from a gas bomb 12; a partial-pressure ratio of the rare gas inside the laser tube 1 is raised and the output of the laser beam L is restored. Thereby, the laser beam L absrobs a halogen compound, and the rate at which the output is lowered is lowered. As a result, even when the number of supplement operations of the rare gas is increased, the output of the laser beam L can be restored and a continuous operation at a definite output can be continued for many hours. |
