基于甲烷的红外吸收光谱,通过光谱拆分法实现了一种双通带滤波器的设计。通过调节离子源束流,改善了ZnS膜层的折射率,消除了背景噪声。通过引入可控薄层,降低了非周期窄带通膜系的制备难度。经实验测试与分析,所研制的双通带滤波器在3.31 μm和7.67 μm的透射率分别为89.25%、81.97%,达到了提高探测系统灵敏度的目的。

Based on the infrared absorption spectrum of methane, a dual-bandpass filter is designed by the spectral splitting. With the adjustment of ion source beams, the refractive index of the ZnS film layer is improved and the background noise is eliminated. The fabrication difficulty of aperiodic narrow-bandpass filter films is reduced by the introduction of controllable thin film layers. The experimental test and analysis show that the prepared dual-bandpass filter possesses the transmissivity of 89.25% at 3.31 μm and 81.97% at 7.67 μm, respectively, and the goal for improving the sensitivity of detecting systems is achieved.