| 摘要 |
PURPOSE:To improve the spectral reflectance by adjusting the optical thickness of the 1st layer having higher refractive index and contacting with a glass substrate and that of the outermost layer having a lower refractive index and contacting with the air to lambda0/8 and by adjusting the optical thickness of each of the intermediate layers having alternately lower and higher refractive indexes to lambda0/4. CONSTITUTION:Layers H having a higher refractive index and layers L having a lower refractive index are alternately formed between a glass substrate G and the open air A, and they are called the 1st, the 2nd - layers in order from the layer contacting with the substrate G. lambda0 is a set wavelength, and for example, it is 500nm. The layers H are made of ZrO2, TiO2 or the like, the layers L are made of MgF2, SiO2 or the like, and the substrate G has about 1.52 refractive index. The thickness of the 1st layer H and that of the outermost layer L are adjusted to lambda0/8, and the thickness of each of the intermediate layers is adjusted to lambda0/4. |
