Monte Carlo simulation of an optical coherence tomography signal in homogeneous turbid media

The Monte Carlo technique with angle biasing is used to simulate the optica l coherence tomography (OCT) signal from homogeneous turbid media. The OCT signal is divided into two categories: one is from a target imaging layer i n the medium (Class I); the other is from the rest of the medium (Class II) . These two classes of signal are very different in their spatial distribut ions, angular distributions and the numbers of experienced scattering event s. Multiply scattered light contributes to the Class I signal as well as th e Class II signal. The average number of scattering events increases linear ly with the probing depth. The Class II signal decays much more slowly than the Class I signal whose decay constant is close to the total attenuation coefficient of the turbid medium. The effect of the optical properties of t he medium on the Class I signal decay is studied.