散射介质成像中的时间门研究

研究了用蒙特卡罗方法模拟均匀散射介质中含有光学性质不同的小球时，漫反射信号随时间的变化，当小球和激励源的相对位置不同时随时间变化的漫反射曲线也不同，利用这种漫反射信号的差异同时结合时间门技术可以对散射介质中一定浓度的物体成像。结论表明成像对比度与时间门的开始时刻和时间门宽度有直接关系。针对小球投影位置漫反射信号的强和弱，分别用半宽度点和最大强度的80％点作为小球办界位置的判断。

Study on Time-Gate in Imaging of Object in a Scattering Medium

By use of the Monte Carlo method, the variations of diffusive reflection with time are obtained in a scattering medium inclusive of the inhomogeneity. The variations are different when the relative position of the inhomogeneity and the light source is defferent. With combination of the difference and time gate methods, the image of the sphere embedded in the depth of the scattering medium are acquired. The results not only show that the contrast of the image is directly related to the start of gate time and time gate width, but also show that according to the brightness and darkness of diffusive reflection in the sphere projection area, the point of 80% or 50% of the maximum diffusive reflection intensity should be judged as the boundary position of the sphere.