<title>Development of fast Monte Carlo simulation</title>

Abstract

Monte Carlo simulations (MCS) of light scattering concentrate on the particle property of the light and follow the path of a single photon penetrating the scattering medium. Although the Monte Carlo technique makes it possible to conduct simulations of media having various shapes and characteristics, it requires a great deal of computational time. In particular, because the calculation time is strongly affected by the distance between the incident and the detection positions, it is very difficult to simulate large media. To overcome this difficulty, we developed a new method that improves the calculation time of MCS by a dramatic reduction in the number of wasted photons. Conventional MCS are made such that the photons are traced in a fixed and well defined 3D space. This space has the exact size and shape of the simulated medium, and the incident and the detection positions are situated accordingly. In developed Transformed Monte Carlo Simulation (TMCS) the photon tracing is done inside a different imaginary simulation space, and a transformation is applied to each photon path in the imaginary simulation space in order to appropriate the photon path inside the model space simulating the scattering medium. Consequently, the calculation time was greatly reduced.