以红外光学和薄膜技术为理论背景, 详细介绍了氧化铝基体表面3.7 μm与4.8 μm双波段带通滤光膜的特性、制备及测试方法。氧化铝(Al2O3)由于其透光区域较宽,牢固度好, 便于光学系统使用而被经常应用于中波红外光学系统中。采用软件优化计算和双面镀制截止带通滤光膜的方案,通过速率控制、离子辅助等工艺方法研制成功了可靠性和光谱特性皆优的双波段带通滤光薄膜。分析认为设计结构和优化算法对于薄膜通带平坦度、截止深度以及透过率有着明显的影响。制备工艺方面, 除了合适的蒸发速率外, 采取缓慢蒸发和弱离子能量辅助也是很重要的关键技术, 最终光谱透过率测试平均大于87%, 通过了环境测试, 符合使用要求。

The characteristics, preparation and testing methods of 3.7 μm and 4.8 μm double band-pass filter on the surface of alumina substrate were introduced in the background of infrared optical and thin film technology. Alumina(Al2O3) was used in medium wave infrared optical systems usually because of its wide light transmission area and good fastness and ease of use in optical systems. The two-band band-pass filter with excellent reliability and spectral characteristics were successfully developed by means of speed control and ion assisted process. The films were characterized by software optimization and double-coating of pass-filters. The analysis shows that the design structure and the optimization algorithm have a significant impact on the passband flatness, cut-off depth and transmittance of the film. Preparation process, in addition to the appropriate evaporation rate, the use of slow evaporation and weak ion energy assist was also very important key technology. The final spectral transmittance test averaged over 87% and passed environmental tests to meet the usage requirements.