| 摘要 |
PURPOSE:To exactly hold a lens without giving damages to it, and to efficiently execute cooling of the lens by forming a coating layer which is hard and excellent in its thermal conductivity such as a diamond-shaped thin film, on the peripheral edge part. CONSTITUTION:On a condensing lens 11, a diamond-shaped thin film 12 is formed as a coating layer to thickness of about 1,000Angstrom . As for a shape of the diamond-shaped thin film 12, the outside diameter and the inside diameter are set to 38.1mm being the same as that of the condensing lens 11, and 35.5mm, respectively, and said film is formed on both faces of the condensing lens 11 in a shape of a ring whose width is about 2.6mm. As for the condensing lens 11, its flat optical surface is placed directly (strictly speaking, through the diamond-shaped thin film 12) on a supporting part of the lower end of a supporting member 21, and also, fixed from upward with an annular screw 24 through an 'O' ring 22 and a holding metalic fixture 23. |
