Efficient numerical modelling of time-domain light propagation in curved 3D absorbing and scattering media with finite differences.

An efficient approach is introduced for modelling light propagation in the time domain in 3D heterogeneous absorbing and scattering media ( biological tissues) with curved boundaries. It relies on the finite difference method (FDM) in conjuction with the Crank-Nicolson method for accurately solving the optical diffusion equation (DE). The strength of the FDM lies in its simplicity and efficiency, since the equations are easy to set up, and accessing neighboring grid points only requires simple memory operations, leading to efficient code execution.