Multi-layered antireflection film

Abstract

Abstract PURPOSE:To obtain a stable reflection characteristic by forming, successively from a glass base plate side, the 1st layer consisting of Al2O3, the 2nd layer laminated with the three layers; a ZrO2 layer, ZrO2-TiO2 mixed layer and ZrO2 layer respectively having specific thicknesses with respect to the design wavelength and the 3rd layer consisting of MgF3 as the multi-layered antireflection film for optical parts on the glass base plate. CONSTITUTION:The 1st layer film having the thickness of lambda0/4 the design wavelength and the 2nd layer film laminated with the three layers; a ZrO2 film having lambda0/4, the mixed film of TiO2/ZrO2=0.07-0.13 having the refractive index slightly larger than the refractive index of said film to lambda0/8 thickness and a ZrO2 film having lambda0/8 thickness are formed on a glass plate successively from the base plate side. MgF2 is then formed to lambda0/4 thickness as the 3rd layer film on the 2nd layer film thereby manufacturing the multi-layered antireflection film. There is therefore no significant influence in the reflection characteristic in spite of a minor fluctuation particularly in production conditions and the antireflection film which has high film strength, decreases peak reflectivity and has at the same time a wide low reflection region is thus obtd. with less variance and at a stable and high yield.

Inventors

• 👤 Takuo Fujino
• 👤 藤野　拓男

Bibliographic Details