中文摘要：

使用经典洛伦兹谐振子模型对热蒸发制备的锗、硫化锌以及低吸收稀土氟化物薄膜的红外透射光谱进行拟合，得出这些材料在中长波红外区的光学常量．使用这三种材料设计并制备了锗窗口7．7～15μm宽带增透膜系，通过优化设计并且使用长波红外区吸收小的低折射率材料，在长波区（13～15μm）的透过率测量值有明显提高，15μm处的透过率为89．9％．

英文摘要：

The middle and long wave infrared optical constants of evaporated films,such as germanium,zinc sulphide,low absorption rare earth fluoride, etc, were obtained by fitting the transmission spectrum based on classical Lorenz oscillator model. Broad band antireflective coating from 7.7 μm to 15 μm had been designed and fabricated using these three materials. The measured transmission in the long wave region （13-15μm） had been improved greatly by refining the design and using the low absorption materials. The measured transmission at 15μm is 89.9%.