Thermal Radiation Properties Control Based On Microstructure

Thermal radiation properties control based on microstructure is using structures of Nano/Microscale whose characteristic dimension is close to incidence wavelength to realize selective control of wavelength. Appling it to realize the multichannel-stealth compatibility will emerge very large potential. For researching the multichannel-stealth compatibility based on microstructure, this paper uses the reciprocity between electromagnetic wave and microstructure to realize selective control of wavelength and designs the microstructure which can meet the multichannel-stealth compatibility requirements of visible light, heat infrared and laser. The detailed research contents are listed in the following.Firstly, the transforming relation between the electric and magnetic field which produced by the reciprocity between electromagnetic wave and microstructure is researched using the Maxwell equations. And the control mechanism of spectral selectively based on microstructure is explored. The control factors are listed in the following two aspects:the material attribute and configuration pattern of microstructure.Secondly, the optimization design method combined by needle optimization method and variable metric optimization method is used to design coatings. A asymmetric Fabry-Perot structure whose absorptance is increased at 10.6um is designed in theory. And the structure is optimized by using numerical calculate method. At the basic of them, a one-dimensional multi-coating is designed to realize the multichannel-stealth compatibility. The result shows that the multi-coating meets the multichannel-stealth compatibility requirement very well.Finally, for selecting material of microstructure, the dielectric constant and dispersion of several materials are researched to fix their ranges of wavelength where the surface electromagnetic waves can be excited. Under the guidance of the moth eye's antireflection performance, numerical calculate method is used to calculate its spectral characteristics for verification the feasibility of using the moth eye microstructure to control the spectrum of 10.6μm. And the influence of the period, diameter of the bottom and the top circle, height and the thickness of basis to microstructure's spectral characteristics are explored. Then, coatings and the frustum microstructure are combined to be a two-dimensional complex microstructure which is optimized further. The result shows that the complex microstructure meets the multichannel-stealth compatibility requirement very well.