| 摘要 |
PURPOSE:To enable an operator to grasp correctly a remaining workable time and to execute reliably a cleaning of optical components and the like by a method wherein a characteristic curve is found from a laser oscillation efficiency and the workable time is calculated and is displayed. CONSTITUTION:Laser output measured by a power sensor 24 is converted into a digital value by an AD converter 25 and is stored in a memory 10, while an output voltage and high-frequency current of a power supply for excitation use are also read in the memory 10. This laser output, the output voltage and the high-frequency current are stored in each time of rise of a laser. An efficiency calculating means 31 finds excitation input from this output voltage and the high-frequency current and finds a laser oscillation efficiency from this excitation input and the laser output. A characteristic curve generating means 32 generates a characteristic curve from this laser oscillation efficiency. A working time calculating means 33 calculates a workable time of up to reach a low limit of laser oscillation efficiency from the characteristic curve and displays the workable time on a display 18. |
