散射体的尺寸参数和折射率对通过混浊介质的偏振门控光学成像的影响。

Influence of size parameter and refractive index of the scatterer on polarization-gated optical imaging through turbid media.

作者信息

Shukla Prashant, Sumathi R, Gupta Sharad, Pradhan Asima

机构信息

Department of Physics and Center for Laser Technology, Indian Institute of Technology Kanpur, India.

出版信息

J Opt Soc Am A Opt Image Sci Vis. 2007 Jun;24(6):1704-13. doi: 10.1364/josaa.24.001704.

DOI:10.1364/josaa.24.001704

PMID:17491639

Abstract

The influence of incident polarized light, refractive index, and size parameter of the scatterer on achievable resolution and contrast (image quality) of polarization-gated transillumination imaging in turbid media is reported here. Differential polarization detection led to significant improvement of image quality of an object embedded in a medium of small-sized scatterers (diameter D<<lambda, isotropic scattering medium, anisotropy parameter g<or=0.2), especially using circular polarization. In contrast, for anisotropic scattering media composed of larger-sized scatterers (D>or=lambda,g>or=0.7), the improvement in image quality was less pronounced using either linear or circular polarization gating when the refractive index of the scatterer was high (ns=1.59), but for a lower value of refractive index (ns=1.37), image quality improved with the differential circular polarization gating. We offer a plausible explanation for these observations.

摘要

本文报道了入射偏振光、折射率和散射体尺寸参数对浑浊介质中偏振门控透射成像可实现的分辨率和对比度（图像质量）的影响。差分偏振检测显著提高了嵌入小尺寸散射体介质（直径D<<λ，各向同性散射介质，各向异性参数g≤0.2）中物体的图像质量，尤其是使用圆偏振时。相比之下，对于由较大尺寸散射体（D≥λ，g≥0.7）组成的各向异性散射介质，当散射体折射率较高（ns = 1.59）时，使用线性或圆偏振门控时图像质量的改善不太明显，但对于较低的折射率值（ns = 1.37），差分圆偏振门控可提高图像质量。我们对这些观察结果给出了合理的解释。