Semi-analytical Monte Carlo simulation for time-resolved light propagating in multilayered turbid media

In this study, a Monte Carlo (MC) method for time-resolved light scattering from multilayered turbid media (SMCML) has been developed. This method is particularly suitable for simulating light backscattering from layered media and receiving the time-resolved signal in a finite sensor area, such as ocean detection, photomedicine and photobiology. The classical semi-analytical MC method requires the scattering events to be located in a single-layer medium. To address the multilayer problem, the energy loss mechanism of photons propagating in tissue was analyzed in this study. According to the energy contribution to the detector, only photons that contribute significantly were considered. Simulations were conducted for stochastic turbid media with different optical parameters. Temporal profiles of the echo signal were obtained with a satisfactory convergence. Compared to the classical MC method, the SMCML method can dramatically reduce the computation time by more than two orders of magnitude.