Effect of photons of different scattering orders on the formation of a signal in optical low-coherence tomography of highly scattering media.

The influence of photons of different scattering orders on the formation of a detected signal in optical low-coherence tomography (OCT) is considered. The scattering orders are estimated by analysing the spatial distribution of the probability density for the effective optical paths of detected photons calculated by the Monte Carlo method. The influence of photons with different scattering orders on the formation of a signal is estimated quantitatively depending on the optical properties of the medium under study. The results of numerical simulations are interpreted within the framework of possible applications of OCT for non-invasive diagnostics of the human skin and other highly scattering random media. It is shown by the example of calculation of OCT signals from model biological tissues that the OCT method gives reliable information on their internal structure from optical depths up to 0.3 mm.