| 摘要 |
PURPOSE:To obtain an effective light reflection film at a near IR wavelength band by using copper for the light reflection film of a polarizing element for near IR rays provided with a polarizing sepn. film on a part of one surface of a transparent flat plate having parallel planes and the light reflection film in a part of the other one surface. CONSTITUTION:A polarizing sepn. film 11 consisting of a laminate of TiO2 and SiO2 havig about 5 micron thickness and a light reflection film 12 consisting of copper having about 400nm thickness are provided on both surfaces of a glass plate 13 and rectangular prisms 14 and 15 having the same refractive index as the refractive index of the plate 13 are stuck on both sides of the plate. The film 12 is formed by partial filming by vapor deposition using a mask in such a way that incident light X11 can be transmitted through the prism 14 to the plate 13 or by mere filming without using the mask then patterning by etching using nitric acid, etc. Since copper has a high reflectivity to near IR light which is a wavelength of a 1-micron band, the decrease in the reflection characteristic of the light reflection film is obviated. |
