Spatial helicity response metric to quantify particle size and turbidity of heterogeneous media through circular polarization imaging

Michael D Singh; I Alex Vitkin

doi:10.1038/s41598-023-29444-9

Spatial helicity response metric to quantify particle size and turbidity of heterogeneous media through circular polarization imaging

Sci Rep. 2023 Feb 8;13(1):2231. doi: 10.1038/s41598-023-29444-9.

Authors

Michael D Singh¹, I Alex Vitkin^{2

3

4}

Affiliations

¹ Department of Medical Biophysics, University of Toronto, Toronto, ON, Canada. michaeldhillon.singh@mail.utoronto.ca.
² Department of Medical Biophysics, University of Toronto, Toronto, ON, Canada.
³ Department of Radiation Oncology, University of Toronto, Toronto, ON, Canada.
⁴ Division of Biophysics and Bioimaging, Princess Margaret Cancer Centre, Toronto, ON, Canada.

Abstract

Backscattered circularly polarized light from turbid media consists of helicity-flipped and helicity-preserved photon sub-populations (i.e., photons of perpendicular and parallel circular handedness). Their intensities and spatial distributions are found to be acutely sensitive to average scatterer size and modestly sensitive to the scattering coefficient (medium turbidity) through an interplay of single and multiple scattering effects. Using a highly sensitive intensified-CCD camera, helicity-based images of backscattered light are captured, which, with the aid of corroborating Monte Carlo simulation images and statistics, enable (1) investigation of subsurface photonic pathways and (2) development of the novel 'spatial helicity response' metric to quantify average scatterer size and turbidity of tissue-like samples. An exciting potential application of this work is noninvasive early cancer detection since malignant tissues exhibit alterations in scatterer size (larger nuclei) and turbidity (increased cell density).

Abstract

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