| 摘要 |
PURPOSE:To obtain an interference filter undergoing a small change in the central wavelength due to a temp. change by suitably combining a substance undergoing a plus change in the refractive index due to a temp. change with a substance undergoing a minus change in the refractive index due to a temp. change to form a multilayer film. CONSTITUTION:A multilayered film is formed by suitably combining at least 1 layer of a film forming substance undergoing a plus change in the refractive index due to a temp. change such as ZnS, SiO2, ZnSe or Ge with at least 1 layer of a film forming substance undergoing a minus change in the refractive index due to a temp. change such as PbTe, PbSe, CaF2, BaF2, LaF3 or MgF2. For example, a band-path filter is manufactured by forming a multilayered film consisting of alternate PbTe and ZnS layers 1-3, 5-7 and a spacer layer 4 made of ZnS having a low rate of change in the refractive index due to a temp. change on a substrate (sapphire) 8. The filter has reduced dependency of the central wavelength position on temp. |
