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1.
Based on the plane wave analysis and the superposition of the plane waves, the diffraction of a Gaussian beam by a periodic screen with a dielectric plate is analyzed. The reflection power coefficient for different parameters of the beam and the screen is given. When the beam waist size is increased the results reaches that of the plane wave. It has been found that the power reflection coefficient is not sensitive to the beam waist size, however, it is sensitive to the period of the grating and polarization angle. 相似文献
2.
两个相邻目标对平面波、高斯波束的光散射 总被引:3,自引:0,他引:3
基于等效原理和互易性定理研究了两个靠近目标对平面波、高斯波束的光散射问题,给出了这一复合光散射模型的二阶散射结果。通常一阶散射结果容易求解,但由于耦合效应的复杂性,很难给出二阶散射结果的解析形式。为了解决这一问题,应用互易性定理给出了求解任意相邻介质目标二阶散射场的公式,同时借助等效原理将求解散射场公式中的体积分简化为面积分的形式,从而降低了求解难度。求解了两相邻球形粒子的复合散射场,并将求解结果与应用时域积分方程法求得的结果进行了比较。同时,还讨论了束腰半径、目标位置对散射截面及偏振度的影响。 相似文献
3.
Terahertz/Millimeter Wave Characterizations of Soils for Mine Detection: Transmission and Scattering
Todd W. Du Bosq Robert E. Peale Glenn D. Boreman 《International Journal of Infrared and Millimeter Waves》2008,29(8):769-781
The detection of anti-personnel mines depends on the soil transmission and scattering at a given wavelength. Transmission
spectra were measured over the range 90–4200 GHz for 19 soil samples that span a number of soil orders that have extensive
worldwide distribution using a vector network analyzer (90–140 GHz) and a Fourier spectrometer (120–4200 GHz). Transmission
drops to nearly zero for wavelengths shorter than the characteristic particle size of the sample as a consequence of scattering.
This interpretation is supported by a fit to a standard scattering model with physically reasonable fitting parameters. Transmission
spectra were also measured for various liquids (90–600 GHz) for possible index matching. These liquids were mixed with the
soil sample and were found to reduce scattering and increase transmission through the soil at higher frequencies. This work
is relevant to mine detection using terahertz and millimeter wave radiation for high resolution images through the soil. 相似文献