| 摘要 |
PURPOSE:To prevent decrease of light transmittance caused by the attaching of dust, moisture condensation, and deliquescence by a method wherein the inside of a laser head is made airtight, and gas such as dry nitrogen and air is sealed therein. CONSTITUTION:A window member 2 and a heat dissipating plate 8 have hermetic structures respectively. An O ring is used to constitute the hermetic structure fastened by screws. Dry nitrogen or air containing no fine particles like dust is sealed in the space in a laser head including optical components 3-7. Breathing of aperture parts of the window member 2, the heat dissipating plate 8, etc., is completely cut out from the outside. Thereby the following can be prevented decrease of light transmittance caused by the attaching of dust and the like to the surfaces of optical components, moisture condensation on a laser diode surface, and absorption by chemical materials and OH radical of water. |
