Abstract
Robust models for single-fiber reflectance (SFR) are relatively complex [Opt. Lett. 45, 2078 (2020) [CrossRef] ] due to overlapping of the illumination and collection areas that entails probability weighting of the spatial integration of photon-remission. We demonstrate, via analytical means for limiting cases and Monte Carlo simulation of broader conditions, that diffuse photon-remission collected by single-fiber geometry may be scaled over the center-illuminated photon-remission. We specify for a medium revealing Henyey–Greenstein (HG) scattering anisotropy that the diffuse photon-remission from a sub-diffusive area of a top-hat illumination is ${\sim}{84.9}\%$ of that collected over the same area when under a centered-illumination. This ratio remains consistent over a reduced-scattering fiber-size product of $\mu _s^\prime {d_{\text{fib}}} = [{{{10}^{- 5}},{{10}^0}}]$, for absorption varying 3 orders of magnitude. When applied to hemoglobin oxygenation changes induced in an aqueous phantom using a 200 µm single-fiber probe, the center-illumination-scaled model of SFR produced fitting results agreeing with reference measurements.
© 2021 Optical Society of America
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