Parvin Reajmina, Roy Abhijit, Varshney Shailendra K, Brundavanam Maruthi M
Appl Opt. 2021 Aug 20;60(24):7259-7267. doi: 10.1364/AO.430164.
The change of the spatial coherence-polarization (CP) property of a speckle pattern due to the modulation of birefringence in a scattering medium is investigated experimentally. The birefringence is introduced to the scattering medium by attaching layers of overhead projector (OHP) sheets to it. It is shown that the spatial polarization distribution can be tuned from a uniformly polarized case to a randomly polarized case by increasing the number of OHP sheets. The change of the spatial CP property with the number of OHP sheets is investigated from the study of the spatial degree of coherence and the degree of polarization, and these variations are further confirmed from the probability density function of the intensity of the speckle pattern and from the measurement of the generalized Stokes parameters. The effect of the change of the number of OHP sheets on the visibility of the intensity correlation function and the quality of the object retrieved through the scattering medium are also investigated.
通过实验研究了散射介质中双折射调制引起的散斑图案空间相干 - 偏振（CP）特性的变化。通过在散射介质上附着多层投影仪（OHP）胶片来引入双折射。结果表明，通过增加OHP胶片的层数，可以将空间偏振分布从均匀偏振情况调整为随机偏振情况。从空间相干度和偏振度的研究出发，探讨了空间CP特性随OHP胶片层数的变化，并且这些变化通过散斑图案强度的概率密度函数以及广义斯托克斯参数的测量得到了进一步证实。还研究了OHP胶片层数的变化对强度相关函数的可见度以及通过散射介质恢复的物体质量的影响。
