红外夜视仪用精密模压硫系玻璃研究进展

Development of Fine Molded Chalcogenide Glasses for IR Night Vision

长期阻碍热成像系统获得商业应用的重要原因之一在于昂贵的成本 ,其中光学部件占很大比重。本综述介绍的低成本、高性能硫系玻璃是取代昂贵的单晶锗应用于热成像仪光学系统的候选材料。采用表面涂抗反射膜的方法可提高玻璃的红外透过率至 97% ,而通过特定的组成设计和晶化处理在玻璃的网络结构中引入纳米尺度的微晶 ,可显著改善硫系玻璃的热、机械性能 ,同时保持原有的红外光学透过性能。用于非晶态材料的精密模压成型工艺则可使加工成本较之用于晶体材料的单点金刚石车削工艺有显著降低 ,可加工包括球面、非球面和非球面衍射棱镜在内的多种硫系玻璃光学元件。以此为光学部件的标准小型非冷却式非晶硅探测器已研制成功 ,其性能与以单晶锗棱镜为光学系统的同类探测器相当 ,全系统温度分辨率达 0 .1℃。

Thermal imaging has long been limited in the sole domain of the miltary because of the high cost of the hardware,mostly the optic.The present article introduced one potential solution to this problem by using chalcogenide glass as a material.To increase the transmission of chalcogenide glass lenses,an antireflection coating can be deposited on the lenses which will results in the average transmission in the range of 8—11 μm increasing from 70% up to approximately 97%.Specific composition design and thermal treatment are effective to improve the thermal and mechanical properties of chalcogenide glass while keeping their original good IR transmittance due to the introduction of nanosized crystals in the glass matrix.The only way for the chalcogenide glasses to be competitive compared to germanium,is to produce the spherical and aspheric lenses by using a molding process,which is much more econo- mic than single-point-diamond turning used for producing germanium lenses.The set of lenses is associated with a standard uncooled microbolometer based on amorphous silicon with the temperature resolution of the whole system up to 0.1℃ which remains the same as the system using classic germanium lenses.