为满足探测1,2丙二醇二硝酸脂有毒气体浓度的红外探测元件抑制带截止深度深、通带内平均透射比高、波纹系数小等要求,采用等效折射率理论与局部优化相结合的设计方法,选用PbTe/ZnSe作为高低折射材料,采用长波通膜系、短波通膜系以及双半波膜系设计了截止深度深、双通道、通带宽度合适的红外滤光片,通带分别为5.9～6.2μm及11.9～12.2μm,通带内平均透射比分别在90%及65%以上;对所设计的膜系进行了薄膜物理厚度和膜层折射率的误差分析。分析表明,薄膜制备时沉积速率精度应控制在3.5%以内,材料折射率的变化应控制在3%以内,与膜层折射率相比,薄膜物理厚度对平均透射比的影响小,并且双半波膜系对厚度以及折射率变化更敏感。 In order to meet the requirements of detecting the concentration of 1,2-propanediol dinitrate toxic gas infrared detection element with deep cut-off depth, high average transmittance in the passband, small ripple coefficient, the use of equivalent refractive index theory and local optimization design Method, using PbTe / ZnSe as the material of high and low refraction, the long-pass film system, the short-wave film system and the double half-wave film system are used to design an infrared filter with a deep cutoff depth, a dual passband and a passband width of 5.9 ~ 6.2μm and 11.9 ~ 12.2μm. The average transmittance in the passband was above 90% and 65%, respectively. The error of the film thickness and film refractive index was analyzed. The analysis shows that the precision of the deposition rate should be controlled within 3.5% and the refractive index of the material should be controlled within 3%. Compared with the refractive index of the film, the influence of the physical thickness of the film on the average transmittance is small, Wave film systems are more sensitive to changes in thickness and refractive index.