| 摘要 |
PURPOSE:To prevent the change with lapse of time in optical characteristics by constituting an adjacent layer to a film with a high refractive index of Al2O3 or a substrate. CONSTITUTION:The film with a high refractive index among the optical multilayered films is made a sandwich structure holding with the Al2O3 or the substrate. The film with a high refractive index preferably consists of one or more components selected from the groups of TiO2, Ta2O5, HfO2, ZrO2, Nb2O5, mixture and worked products thereof, in respect of optical characteristics (refractive index, low absorbability), mechanical strengths and cost, etc. These high refractive films are selected by the wavelength and the environment for in which an optical element is used and are selected from between HfO2 and ZrO2 in an UV region, and are used by selecting from the groups of TiO2, Ta2O5, ZrO2, Nb2O5, and these mixtures and the worked products in the visible light region. Thus even in the case of vapor-depositing at a low temperature, the optical characteristics are caused no change with lapse of time. |
