超宽频带THz脉冲在随机散射介质中传播的理论研究

Theoretical Study of Propagation of Ultra-wideband THz pulse in Random Scattering Media

研究了超宽频带THz脉冲入射到散射介质中时其透射脉冲的时空特性 根据Mie理论计算出随机散射介质的散射系数和各向异性因子 ,用时间分辨MonteCarlo方法模拟了超宽频带的THz脉冲在随机散射介质中的传播 ,研究了在不同散射颗粒半径 ,不同频宽的THz入射脉冲对透射脉冲的影响和散射对成像分辨率的影响 结果表明 :散射会降低THz脉冲在随机散射介质中的成像分辨率 ,散射颗粒越小 ,散射介质越厚 。

Propagation of an ultra-wideband THz pulse in random scattering media is described using Monte Carlo simulation. We study the effects of the radius of scattering spheres and the depth of scattering media, in relation to the parameters of scattering coefficient and anisotropic factor calculated by Mie theory. The results show that the smaller the spheres are, the most THz photons is scattered as Mie theory holds. The scattering effect expands in the width of transmitted pulse in temporal domain and reduces the imaging resolution of THz pulse in random scattering media.