Care & Health Applications Group, Philips Research Europe, High Tech Campus 34, 5656AE Eindhoven, The Netherlands.
Sensors (Basel). 2013 Sep 17;13(9):12527-35. doi: 10.3390/s130912527.
The polarization characteristics of birefringent tissues could be only partially obtained using linearly polarized light in polarization sensitive optical imaging. Here we analyze the change in polarization of backscattered light from birefringent structures versus the orientations of the incident polarizations using linearly, circularly and radially polarized light in a cross-polarized confocal microscope. A spatially variable retardation plate composed of eight sectors of λ/2 wave plates was used to transform linearly polarized light into a radially polarized light. Based on the experimental data obtained from ex-vivo measurements on human scalp hairs and in-vivo measurements on hair and skin, we exemplify that the underestimation of the birefringence content resulting from the orientation related effects associated with the use of linearly polarized light for imaging tissues containing wavy birefringent structures could be minimized by using radially polarized light.
在偏振敏感光学成象中，采用线偏振光只能部分获得双折射组织的偏振特性。本文在交叉偏振共焦显微镜中，采用线偏振、圆偏振和径向偏振光，分析了双折射结构后向散射光的偏振随入射偏振光取向的变化。采用由八个λ/2 波片扇形区组成的空间可变延迟片，将线偏振光转变为径向偏振光。根据从人体头皮毛发离体测量和毛发及皮肤活体测量所得到的实验数据，举例说明了采用径向偏振光，可使与成像含有波浪形双折射结构的组织时有关的与取向有关的效应相关联的双折射含量的低估最小化。
