A three dimensional (3D) photon transport model has been developed based on the frequency domain simplified
spherical harmonics approximation (SP<sub>N</sub>) to the Radiative Transport Equation. Based on preliminary Monte Carlo
studies, it is shown that for problems exhibiting strong absorption, the solutions using the 7th order SP<sub>N</sub> model (N = 7) are
significantly more accurate than those from a standard Diffusion (SP<sub>1</sub>) based solver. This advance is of particular
interest in the field of bioluminescent imaging where the peak emission of light emitting molecular markers are closer to
the visible range (500 - 650 nm) corresponding to strong absorption due to hemoglobin.