| 摘要 |
PROBLEM TO BE SOLVED: To provide an optical element which ensures a sufficient film thickness and a low refractive index of a low refractive index layer as well as has high scratch resistance and high antireflection performance with little fluctuations in the characteristics due to the film thickness.SOLUTION: An optical element 1 is provided, which is composed of a first layer (a second inorganic compound layer 22) disposed above a transparent substrate (transparent substrate 10) and a second layer (first inorganic compound layer 21) disposed between the transparent substrate and the first layer. The first layer has a uniform refractive index and a physical film thickness four times or more of the center wavelength of light to be used. The refractive index of the first layer is lower than the refractive index of the second layer. |
