Detection of virus particles by scattering field using the multiperspective polarization modulation imaging method

Abstract

The polarization parametric indirect microscopic imaging (PIMI) method, which employs a polarization-modulated incidence illumination and fitting the far-field variation of polarization states of scattered photons, is capable of direct identification of subdiffraction-scale structures and substances, such as virus particles. However, in the present strategy, the optical elements that collect the scattered photons are nearly fixed above the sample, making the collected information relatively limited, as the side-scattering photons are not fully utilized. To address this problem, we propose a multiperspective PIMI imaging method to maximize the collection of scattering photons from different spatial directions, which can obtain more information of optical anisotropy among particles. As a proof-of-concept study, virus detection using such a method is performed theoretically and experimentally. Results reveal that the virus particles can be detected and determined more distinctly thanks to the set of PIMI images from different spatial angles, showing notable superiority to the previous scheme, where only a plane PIMI image is derived from a fixed spatial direction. With the capability of acquiring more characteristics of the samples, the proposed multiperspective PIMI method can be applied in many fields, such as morphological characterization and biosensing.