Chen Li, Chen Ziyang, Singh Rakesh Kumar, Pu Jixiong
Opt Express. 2020 Mar 16;28(6):8145-8155. doi: 10.1364/OE.382551.
Light propagating through a scattering medium generates a random field, which is also known as a speckle. The scattering process hinders the direct retrieval of the information encoded in the light based on the randomly fluctuating field. In this study, we propose and experimentally demonstrate a method for the imaging of polarimetric-phase objects hidden behind a scattering medium based on two-point intensity correlation and phase-shifting techniques. One advantage of proposed method is that it does not require mechanical rotation of polarization elements. The method exploits the relationship between the two-point intensity correlation of the spatially fluctuating random field in the observation plane and the structure of the polarized source in the scattering plane. The polarimetric phase of the source structure is determined by replacing the interference intensity in traditional phase shift formula with the Fourier transform of the cross-covariance of the intensity. The imaging of the polarimetric-phase object is demonstrated by comparing three different phase-shifting techniques. We also evaluated the performance of the proposed technique on an unstable platform as well as using dynamic diffusers, which is implemented by replacing the diffuser with a new one during each phase-shifting step. The results were compared with that obtained with a fixed diffuser on a vibration-isolation platform during the phase-shifting process. A good match is found among the three cases, thus confirming that the proposed intensity-correlation-based technique is a useful one and should be applicable with dynamic diffusers as well as in unstable environments.
光在散射介质中传播会产生一个随机场,该随机场也被称为散斑。散射过程阻碍了基于随机波动场直接获取光中编码的信息。在本研究中,我们提出并通过实验证明了一种基于两点强度关联和相移技术对隐藏在散射介质后的偏振相位物体进行成像的方法。所提方法的一个优点是它不需要偏振元件的机械旋转。该方法利用了观测平面中空间波动随机场的两点强度关联与散射平面中偏振源结构之间的关系。通过用强度的互协方差的傅里叶变换代替传统相移公式中的干涉强度来确定源结构的偏振相位。通过比较三种不同的相移技术来展示偏振相位物体的成像。我们还在不稳定平台上以及使用动态漫射器评估了所提技术的性能,动态漫射器是通过在每个相移步骤中用一个新的漫射器替换原来的漫射器来实现的。将结果与在相移过程中使用固定漫射器的隔振平台上获得的结果进行了比较。在这三种情况下发现了很好的匹配,从而证实了所提的基于强度关联的技术是一种有用的技术,并且应该适用于动态漫射器以及不稳定环境。