| 摘要 |
PURPOSE:To prevent an excessive temperature rise of a reflecting layer by allowing light to enter a transparent substrate of glass, etc.,from its surface side, reflecting the light by the reflecting layer formed on the reverse surface of the substrate, and cooling it by a refrigerant. CONSTITUTION:On a light incidence surface side, a transparent substrate 3a of quartz glass, etc., is arranged and on its reverse surface, a reflecting layer 3b is formed by vapor-depositing aluminum or gold. Further, a refrigerant 6 such as cooling air flows along the reverse surface of the reflecting layer 3b. |
