During the bimonthly Debye lunch lectures, young scientists from the Debye Institute for Nanomaterials Science present their research. This lunch lecture, Imaging objects through thin scattering media by retrieval of the scattered point spread function, will be given by Abhilash Thendiyammal from the Nanophotonics research group.
Imaging of objects through turbid layers is a challenge as the wavefront of the incident light is distorted by scattering due to the inhomogeneous distribution of the refractive index of the media. We demonstrate a high-speed technique to image incoherently illuminated hidden objects by retrieving the speckle-like point spread function (PSF) of the scatterer. We make use of the prior knowledge of an object of known shape and a single shot deconvolution algorithm to extract the PSF of the scatterer. Our method gives sharp and clean reconstructed images and is so robust that the reconstruction is possible even with a part of the acquired image. Further, we extend the technique to image objects in scenarios where the reference object is spectrally and spatially separated. This is achieved by introducing an appropriate spectral/spatial scaling to the retrieved PSF of the scatterer with respect to the unknown object of interest. These methods may have possible future applications in the field of security monitoring and bio-medical imaging.
. “Imaging objects through scattering layers and around corners by retrieval of the scattered point spread function”. Xiaoqing Xu, Xiangsheng Xie, Hexiang He, Huichang Zhuang, Jianying Zhou, Abhilash Thendiyammal, Allard P Mosk, Optics Express. 25 (26), 32829-32840 (2017).
. “Imaging of objects through a thin scattering layer using a spectrally and spatially separated reference”. Xiaoqing Xu, Xiangsheng Xie, Abhilash Thendiyammal, Huichang Zhuang, Junpeng Xie, Yikun Liu, Jianying Zhou and Allard P Mosk, Optics Express,26 (12), 15073 -15083 (2018).