Short pulse laser propagation through tissues for biomedical imaging

An experimental and numerical study is performed to analyse short pulse laser propagation through tissue phantoms with and without inhomogeneities embedded in it. Short pulse laser probing techniques have distinct advantages over conventional very large pulse width or cw lasers primarily due to the additional information conveyed about the tissue interior by the temporal variation of the observed signal. Both the scattered temporal transmitted and reflected optical signals are measured experimentally using a streak camera for samples irradiated with a short pulse laser source. Parametric study involving different scattering and absorption coefficients of tissue phantoms and inhomogeneities as well as the detector position and orientation is performed. The temporal and spatial profiles of the scattered optical signals are compared with the numerical modelling results obtained by solving the transient radiative transport equation using the discrete ordinates technique.