| 摘要 |
PURPOSE:To prevent a laser output from being lowered until impurity concentration is saturated at the initial stage of laser operation by providing a laser gas purifying device, and encapsulating impurity gas produced during laser oscillation in a discharge tube beforehand. CONSTITUTION:A laser oscillator 1 is supplied with given mixing ratio laser gas from a laser gas supply device 2 and a given amount of impurity from an impurity addition device 4. After completion of the supply of the laser gas and the impurity to the laser gas and the impurity to the laser oscillator 1, there are started simultaneously laser oscillation of the oscillator 1, laser gas purification by a laser gas purifying device 4, and laser gas supply by the device 2 for making constant the laser gas mixing ratio. Since impurity concentration in the laser gas remains unchanged so long as operation conditions of the oscillator 1, the device 2, and the device 3 are altered, the laser output is prevented from being lowered owing to the increase of the impurity concentration and hence a stable laser output can be maintained over a long period. |
