Optical Element and Method for Manufacturing Optical Element

Abstract

A multilayer optical thin film 4 is formed on the surface of a substrate 1 made of quartz having a thickness of 0.8 mm or less by alternately laminating SiO2 thin films 2 and Nb2O5 thin films 3 for a total of approximately 100 layers. The linear expansion coefficient of the substrate 1 is small, and the difference from that of the multilayer optical thin film 4 is large. Therefore, when the substrate 1 is lowered to ordinary temperature from the film formation state that is normally at approximately 200° C., the compressive stress of the multilayer optical thin film 4 and the thermal stress that is generated as a result of the temperature drop cancel each other out, so that deformation (warpage) of the substrate 1 is alleviated. Accordingly, when the substrate 1 is cut by a dicing saw or the like, working is easy, there is little damage, and the surface precision of the cut-out optical elements is improved.

Dependencies are inferred from the claim text.