摘要 |
<p>An anti-reflection film provided on a surface of a chalcogenide glass base includes a first thin film layer and a second thin film layer. The first thin film layer is composed of a single layer of Bi2O3 formed by ion beam assisted deposition. The second thin film layer made of YF3 includes assisted layers and non-assisted layers laminated alternately. The assisted layers are formed by the ion beam assisted deposition, while the non-assisted layers are formed without assistance of an ion beam. The assisted layer is superior in adhesion and surface flatness or smoothness. On the other hand, the non-assisted layer has small internal stress. The second thin film layer functions as a buffer to relieve the internal stress of the first and second thin film layers.</p> |