基于偏振门技术,提出了利用漫后向散射光随线偏振光入射方位的变化来测量双层模型表层的粒子尺寸分布及相对折射率。双层物理模型用来模拟上皮组织,上层分别由聚苯乙烯小球或HeLa细胞悬浮液组成,下层由脂肪乳溶液组成,每层的光学特性与上皮组织光学特性匹配。根据米氏(Mie)散射理论,建立了与散射体形态参量相关的偏振后向漫散射强度随入射偏振方位变化的理论模型,并采用浮点遗传算法反演程序获得表层粒子的尺寸分布(PSD)及相对折射率。将理论值和实验测量值进行比较。研究结果表明通过测量随方位变化的后向漫散射光的偏振差分信号,能够获得类上皮组织模型表层的形态结构信息。

The measurement of particle size distribution and refractive index of the thin layers in two-layer tissue phantoms by using the diffuse backscattering light dependent on the azimuth angle of the linearly polarized incident light. In the two-layer model, the upper layer consists of polystyrene pheres suspension or HeLa cells, and the bottom layer is intralipid solution. Optical properties of both layers are supposed to match those of biological tissue. Based on Mie theory, the theoretical model for dependence of particle morphological parameters related polarized diffuse backscattering light intensity on the polarization angle of the incident light is built up. The particle size distribution and relative refractive index are derived by using inverse program of floating genetic algorithm. Comparison of theoretical and experimental results are made, and it is found that the morphological structure information of thin layer tissue can be drawn by measuring and analyzing the polarized differential signal of the azimuth angle-dependent diffuse backscattering light.