| 摘要 |
PURPOSE:To obtain a stable laser output even when a laser is stopped for a long period, by calculating the amount of injection of a mixed gas of a noble gas and a buffer gas on the basis of a calculated oscillation stop time and by injecting the mixed gas by the calculated amount of injection before oscillation of the laser. CONSTITUTION:When an oscillation stop time T exceeds a lower-limit time Tt for output correction, a Kr-Ne mixed gas is injected to compensate lowering of a laser output. A controller checks the presence or absence of a gas replacement request signal first, and when a request for replacement is present, it compares a power lock charging voltage Vp with a Kr-Ne mixed gas injection charging voltage Vc. When this comparison shows that Vp<=Vc, gas replacement is executed with the same gas composition as that in the previous gas replacement. When Vp>Vc, however, the gas replacement is executed with the gas composition obtained by changing a filling pressure of the Kr-Ne mixed gas in accordance with DELTAV (Vp-Vc). In other words, the gas replacement is executed with the filling pressure of the Kr-Ne mixed gas increased as the value of DELTAV increases. |
