| 摘要 |
PURPOSE:To prevent dewing at the external surface of output mirror and avoid crack thereof by providing, between an output mirror and a sending port corresponding to an object, a surrounding part which surrounds them, supplying the dry air thereto from a dry air supplying means and then exhausting the air from an exhausting port. CONSTITUTION:A discharge tube 2 which is filled with a gas medium 3 such as carbonic acid gas, nitrogen gas and helium gas is mounted to a base 1A through a supporting means 1B, DC voltage 5 is applied across an anode 4A and a cathode 4B projecting opposingly each other within said discharge tube in order to excite a medium 3. Thereby a laser beam 6 is generated. This laser beam 6 is resonated between a reflection mirror 7 and an output mirror 8 provided at both ends of the discharge tube 2 and extracted to the outside. In such constitution, a surrounding part 15 which surrounds the output laser beam 6 is provided while being supported by the supporting means 1C is provided and a dewing preventing device 20 consisting of an air drying means 21, air supply port 22 and air exhausting port 23 is connected thereto. Thereby, the dry air sent from a device 20 is blown to the external surface of output mirror 8. |
