| 摘要 |
PURPOSE:To prevent deterioration of a reflection preventing film of a window by forming a thin film having infrared absorption function to an inner side of a pair of Brewster tubes which are connected to extend both ends of a discharge tube and provided with a window at an end side. CONSTITUTION:An anode 4 and a cathode 5 are arranged in opposition each other at both end sections of ceramic tube 2 and connected through a connecting member 2a. A metal vapor source 1 is arranged which enables production of metal vapor inside the ceramic tube 2. An insulator 13 is positioned in an outer periphery of the ceramic tube 2 and a metallic body 9 is arranged at an outer periphery thereof. A Brewster tube 11 is connected to an outer surface of an electrode supporting flange 7. A gus supply tube 3 is provided to the left Brewster tube 11 and a gas exhaust tube 8 is provided to the right Brewster tube 11. An output mirror 14a and a total reflection mirror 14b are provided respectively outside a window 12 of the Brewster tube 11. The window 12 is coated with a reflection preventing film to prevent transmission loss of laser light. Here, surface treatment such as oxidation or nitriding is performed to an inner surface of the Brewster tube 11 to form infrared reflection preventing film 22. |
