Analysis And Control Of Infrared Radiation Characteristics Of Periodic Multilayer Structure

Microstructure refers to a special structure in which the characteristic size of a structure composed of one or more materials is equivalent to the magnitude of thermal radiation wavelength,and even smaller than the wavelength of thermal radiation.With the advancement of modern science and technology,traditional machinery,electronics,aerospace and other aspects of equipment to meet the requirements of miniaturization,integration,equipment manufacturing technology and technology gradually developed to the micro field.The periodic multi-layer film structure can utilize micro-scale radiation effects to achieve certain specific optical properties through the design of the structure.At present,in the field of photoelectric conversion,aerospace,optics and other fields,there have been many aspects of research,through the use of these special effects of the microstructure surface,through specific designs to meet certain specific industrial requirements.This thesis mainly adopts the transmission matrix method and the finite-difference time domain method to study the infrared radiation characteristics of the periodic multi-layer film structure.The purpose is to achieve infrared regulation through the periodic multilayer film structure.The main contents and conclusions include:Based on the transmission matrix method and the Smith equivalent medium theory,the radiation characteristics of the Zn Se / Ag / Zn Se periodic multilayer structure were calculated,and the equivalent refractive index and equivalent wave impedance of the periodic multilayer structure were calculated.Based on the analysis of the causes of the peaks and troughs in the radiation characteristic curve of the multilayer film structure,the influence of FP resonance on the radiation characteristics of the multilayer film structure was discussed.Finally,the effects of different film thicknesses of the multilayer film structure,physical properties of the film structure,the number of cycles of the film structure,and other parameters on the radiation characteristics of the structure are analyzed.By designing the heterogeneous film structure,the infrared is realized.The window is compatible with stealth.For the active detection of stealth technology,using the method of increasing the middle defect layer,based on the passive detection of infrared stealth,the active detection stealth of the structure for a specific wavelength is realized.The radiation characteristics of the multi-layer film structure with cavity structure were calculated by finite-difference time domain method and compared with the radiation characteristics calculated by the transmission matrix method.The correctness of the calculation method was verified.Afterwards,the radiation characteristics of the simple periodic cavity structure were calculated by finite-difference time domain method,and the effects of cavity period,cavity size,and cavity shape on the infrared radiation characteristics of the periodic cavity structure were studied.Based on this,the microstructure with active detection laser stealth is designed and studied.The effects of different cavity shape multilayer microstructures on the infrared radiation characteristics of the structure are discussed.The different electromagnetic wave incidence direction is discussed for different cavities.The effect of the infrared radiation characteristics of the multi-layer microstructure on the shape of the multi-layered structure was found to be influenced by both the surface plasmon polariton and the microcavity resonance effect,and the structure shape and the different light source incident angle stimuli.These two effects are produced.The radiative properties of a periodic multi-layer film structure with a truncated-cone structure layer were calculated by finite-difference time domain method,and compared with the radiation characteristics of a periodic multi-layer film structure and a simple periodic multi-layer film structure with a cavity structure.The structure was found to have high reflectivity and low transmission in the short infrared wavelength band.After that,the influence of the size,structure period,and composition materials of the circular table structure on the radiation characteristics of the structure was calculated.As a result,it was found that the size of the circular table structure affects the peak value of the reflectance,and the period of the structure affects the size of the reflection broadband.