【摘要】 基于光在生物组织中的传输理论,研究有限宽光束在生物组织中的传输特性.利用入射光强与格林函数进行卷积计算,推导了有限宽光束在圆柱坐标系下的光传输过程,给出了有限宽光束的光传输方程.以高斯光源和平圆光源为例,进一步给出了两种光源的有限宽光束在生物组织中的光传输方程.介绍了Monte Carlo方法原理及模拟光在多层生物组织中的传输过程.给出了典型三层生物组织的散射系数、吸收系数和折射率等光学参数.利用Monte Carlo方法模拟了有限宽光束在三层生物组织中的传输特性,对比研究了高斯光源和平圆光源有限宽光束在三层生物组织传输时光学参数漫透射率、漫反射率和光能流率的变化规律.这些参数的变化规律可为光在生物组织传输的实际应用提供理论指导.更多还原

【Abstract】 Based on the transport theory,the transport for photon beams of finite size was researched in this paper.The distribution for photon beams of finite size in multi-layered biological tissues was deduced in a cylindrical coordinate system through the convolution between intensity function of photon beams and Green function,and the distribution equation for photon beams of finite size was presented.The distribution equations in case of Gaussian beams and circularly Flat beams were obtained further.The theory of Monte Carlo(Mc)method was introduced,and the transport of photon beams in multi-layered biological tissues was described by Mc simulation.The optical parameters of a typical three layers biological tissue were given,such as absorption coefficient,reflection coefficient,index of refraction and so on.The transport for photon beams of finite size in the three layers biological tissue was simulated by Mc method.The change rules of optical properties(namely diffuse reflectance、transmittance and fluencies)of the three layers biological tissue were researched for Gaussian beams and compared with those of circularly Flat beams,which can give theory guidance for practical applications.更多还原