Reserch And Fabrication Of Multi-Band Infrared Film On Zns Substrate

Based on the military purpose of the infrared detector window, this article used CVD ZnS as a substrate to fabricate a multi-band filter to meet the requirements at1.064μm and3～5μm of which average transmittance must be more than80%respectively,380nm-980nm band average transmittance is less than5%while an average cut-off of not less than50%being achieved at1.2～2.7μm. According to multi-layer design principle, Macleod and TFCalc coating design software were used to make optimization on the film stack with consideration about the special requirements of multi-band and material properties of the membrane system. By electron beam evaporation and ion assisted deposition techniques, the process parameters were constantly adjusted to have the thickness control error reduced. Ultimately, the film was made to meet the detector requirements well with good optical performance and repeatability as well as mechanical features.