Thermal Radiation Spectral Control Properties Of Microstructure And Their Application

With a growing progress in the realization of nature in the world, the conventional thermal radiation analyses in macroscopic and large scale gradually extends in microcosmic and small scale. When the characteristic length becomes comparable to thermal radiation photon wavelength, magical and complicated phenomena are showed in the course of interplay between thermal radiation and microstructure. The existed researches have given many evidences that the interplay effect and thermal radiation energy transmission could be controlled by adjusting its configuration of microstructure, and this topic is correlated to thermal spectral control using microstructure issue. Recently, with the development in MEMS microstructure fabrication technology, there has been a growing interest in realization of the theme of thermal spectral control using microstructure., and it is considered that this theme will be applied in many fields relating to thermal radiation widely. This dissertation will give explorations to its spectral control properties and applications on the theme of thermal spectral control using microstructure.The detailed contents in this dissertation are listed in the following aspects.1. Thermal radiation energy transmission in Nano/MicroscaleThermal spectral control using microstructure is explored based on electromagnetic wave theory. The Maxwell equations are used to show the inducing relations between the electric and magnetic component. Others aspects are also investigated including the propagation characteristics of thermal radiation wave and its polarization. The fundamental course of the interplay effect is presented between thermal radiation and microstructure, which will be used to direct the thermal spectral control investigation. The FDTD algorithm is proposed by discretizing the Maxwell curl equation in Yee cell. The incidence wave introduction and the boundary condition technique are given to apply in FDTD simulation. This dissertation also discusses the optic parameters of microstructure materials, and gives summaries on microstructure materials.2. Thermal spectral control properties of one-dimensional microstructureThe spectral control properties of one-dimensional periodic microstructure (1DPMS) are simulated and investigated by the proposed FDTD algorithm, also, the effects to the spectral control properties are simulated and analyzed from several influencing factors including incident angle, polarization, configuration parameters, period and the ratio of refraction index. The valuable methods are proposed in order to extend the limited spectral control band of 1DPMS, accordingly, 1DPMS is developed to one-dimensional non-periodic microstructure (1DNPMS). The spectral control properties of 1DNPMS are presented and simulated by FDTD method. The effects from incident angle and polarization to the spectral control properties of 1DMPMS are simulated and analyzed with comparing to those of 1DPMS. The methods are proposed for designing 1DPMS and 1DNPMS, respectively.The spectral control properties of 1DPMS are used to explore the structure color of Morpho butterfly. This dissertation is proposed 1DPMS model for the scale microstructure of Morpho butterfly, and simulated its spectral properties by FDTD algorithm, simulated and analyzed the effect to the spectral properties from the microstructure parameters, incident angle and refraction index of the scale microstructure. Finally, the structure color of Morpho butterfly is analyzed and explained based the simulated results.3. The spectral control properties of one-dimensional microstructure filterThe spectral control properties of One-dimensional microstructure are introduced to develop spectral control filter for thermophotovoltaic (TPV) system with GaSb cell. This dissertation analyzed the matched characteristics with GaSb cell and the power distribution of radiator. 1DPMS filter is designed according to the matched characteristics. The designed filter is simulated and analyzed for its spectral control properties and the spectral control effect from incident angle and polarization. And the designed filter is fabricated by PVD technique. The spectral control properties of the fabricated component are measured and used to evaluate its spectral control performance. Also, 1DNPMS filter is designed according to the matched characteristics. And the 1DNPMS filter's spectral control properties are simulated and used to evaluate its spectral control performance, which is compared to those of 1DPMS filter component.4. Spectral control to the variable emittance materialThe spectral control properties of one-dimensional microstructure are used to control the spectral properties of (La_1-xSr_x)MnO₃ in order to reduce and restrain its absorption within the solar radiation wavelength ,which is one kind of variable emittance material. One-dimensional microstructure is designed according to itself spectral properties and the temperature of its applied circumstance. The designed structure is simulated by FDTD method so that its spectral control performance is evaluated.5. The spectral properties of two-dimensional roughness surfaceThis dissertation investigates the shape of two-dimensional roughness surface, and proposes the model for the roughness surface. The method is given to form the roughness surface. The FDTD algorithm is used to simulate and calculate the bidirectional reflectivity of the two-dimensional roughness surface, and the simulated results are compared with the measured data, GOA simulating results and EMT simulating ones from other references. Also, the spectral properties distribution and its influencing factor are analyzed according to the FDTD simulating results.This dissertation presents the configuration characteristics of two-dimensional grating artireflection-structured surface, and provides designing method for the periodic surface. The artirecflection-structured surface is designed using silicon material in order to achieve spectral control in the wavelength of 0.2～0.3μm. FDTD method is used to simulate and investigate the spectral properties of the designed surface and the effects to its spectral properties from the height and width of characteristic cell, incident angle and polarization.