摘要
硅由于透光区域较宽,便于光学系统使用而经常应用于中波红外光学系统中。但是,以其作为基底,镀制0°～22.5°入射、633 nm与3.5～4.1μm双波段的反射膜却具有相当大的难度,尤其是φ300 mm等大尺寸硅镜引起的牢固度问题。以红外光学和薄膜技术为背景,介绍了大尺寸硅基体反射膜的特性、制备及测试方法。由于红外区可选用的薄膜材料较少,兼顾膜层的制备、光谱特性及可靠性满足等方面因素,最终采用氟化镱(YbF3)作为低折射率材料。经过多次实验,采用速率控制、离子辅助等工艺方法,选取合适的基底温度,解决了在大尺寸硅基体上由于膜层过厚以及YbF3膜层严重应力作用而导致的膜层龟裂问题,最终研制成功符合使用要求,且可靠性和光谱特性皆优的双波段反射薄膜。
Silicon is usually used to make lens for mid-infrared optical system because of its wideband transmission region. But as a substrate, in the case of 0°-22.5° incident angle, it was very difficult to deposit dual-band reflection coatings on Si, especially for the durability of Ф300 mm large size lenses. Infrared optics and thin film technology as the background, the characteristics, preparation and testing methods of reflection coatings on large size silicon substrate were reported. Since there were very few materials with good characteristics for infrared region to be chosen, it was much more difficult to obtain a good coating which had both good transmittance and durability. Ytterbium fluoride （YbF3） was adopted as low-index material at last in consideration of choosing IR coating materials and meeting the spectra requirement. But the severe stresses of YbF3 would result in chapping if there was not a suitable depositing condition. This problem was solved by utilizing improved techniques such as rate-control, ion beam assisted deposition and feasible deposition temperature. The durability, stability and spectra characteristics were all advanced.
出处
《红外与激光工程》
EI
CSCD
北大核心
2012年第7期1854-1857,共4页
Infrared and Laser Engineering
基金
固体激光技术国家重点实验室基金(914100C04)
关键词
红外光学
大尺寸硅镜
高反射膜
牢固度
infrared optics
large size silicon lens
high reflectivity coatings
durability
