混浊介质中线偏振光和圆偏振光的后向漫散射特征

Diffuse Backscattering Characteristic of Linearly and Circularly Polarized Light from Turbid Media

以标准的组织模型Intralipid脂肪乳溶液为研究对象,采用CCD偏振成像系统,通过测量该混浊介质的后向漫散射光的斯托克斯矢量,深入研究了不同方位的线偏振光及不同旋向的圆偏振光入射时,后向漫散射光的特征.研究结果表明:对不同的入射偏振态,后向漫散射强度、偏振度的空间分布具有方位选择性,强度和偏振度的大小随距离入射点的距离增加而减小;介质浓度增加,后向散射强度增加,偏振度减小,且同一浓度下,圆偏振光的偏振度总是高于线偏振光.

The polarization properties of light backscattered from the Intralipid solution as tissue phantom were investigated in different input polarization states,different input azimuth angle using CCD experiment system for measuring Stokes vector. The results indicate that the intensity and degree of polarization patterns depend on the orientation of linearly polarized incident light and the rotary direction of circularly polarized incident light, and their magnitudes decrease with increasing distance from the point of light incident. In addition, the backscattering intensity increases as the media concentration increases for each input polarization state, whereas the media concentrations is larger than 2.5 % ,the backscattering intensity saturates. And the degree of polarization decrease as the concentrations increasing. Comparison of the linearly polarization light to the circularly polarization light, the degree of circular polarization is lager than the degree of linear polarization for the same concentration.