| 摘要 |
PURPOSE:To reduce the thermal gradient of optical parts and to attain protection against breakage, etc. by providing a heater to the circumference of optical parts for a power laser, and amplifying the difference between the output of a sensor which detects the temperature of the optical parts and a reference temperature signal and controlling the heating of the heater. CONSTITUTION:A heater 2 is provided to the circumference of a window material 1 made of the optical parts for the power laser such as a lens. The heater 2 is made of, for example, a sheathed heater and a sensor 3 detects the temperature of the window material 1. The difference between the detection signal of the sensor 3 and reference temperature signal is amplified by a differential amplifier 7 and the heating value of the heater 2 is controlled on the basis of the output signal of the amplifier 7. Thus, the thermal gradient of the window material 1 is reduced as much as possible to prevent the breakage of optical parts of the window material 1 during laser irradiation and to eliminate variation in convergence effect. |
