Development Of Short And Medium Wave Infrared Imaging System Optical Coating

With the continuous development of infrared optical technology,the short-medium-wave infrared imaging system has been a hot topic of research in recent years with its obvious advantages of identification and detection.The chalcogenide glass is the main optical component,with a mature preparation process,the chalcogenide glass is gradually replacing Ge crystal and become a kind of widely used material in infrared heat imaging system.Chalcogenide glass as non-oxide glass,chalcogenide glass is characterized by low refractive index coefficient of temperature,high infrared transmittance,and variable refractive index which is achieved varying the composition ratio.Based on the film design theory,a design of anti-reflective coating for short and medium infrared wave was completed by using software.Based on the calculation and analysis of the thermal stress of the material,a mixed material M-11 was developed as the connecting layer,the parameters of the deposition process were optimized,and the coating structure was modified according to its mechanical properties,which solved the problem of stripping of chalcogenide glass.The results of the spectral tests show that the average transmittance in the bands of 1.4~2.5μm and 3.5~4.5μm are 95.8% and 96.7%,respectively,which satisfy the requirement of infrared imaging system.