| 摘要 |
PROBLEM TO BE SOLVED: To provide an antireflection film having the antireflection characteristics in both zones of 3 to 5 μm and 8 to 12 μm wavelengths of IR rays, and to provide an optical film for a beam splitter and a beam splitter to separate IR rays into two wavelength zones of 3 to 5 μm and 8 to 12 μm. SOLUTION: The antireflection film for an IR region having the antireflection characteristics in two zones of 3 to 5 μm and 8 to 12 μm wavelengths in the IR region is obtained by forming a multilayered film from materials selected from Si, Ge, ZnS, ZnSe, metal oxides and metal fluorides on a Ge or ZnS substrate. The optical film for a beam splitter and a beam splitter element to separate light into two zones of 3 to 5 μm and 8 to 12 μm wavelengths are obtained by combining alternately deposited layers of Ge and ZnS, a metal oxide layer and a metal fluoride layer on a ZnS substrate. |
