Measurement of the optical properties of the skull in the wavelength range 650-950 nm

The optical properties of samples of bone from pig skull have been measured over the wavelength range 650-950 nm. The scattering phase function was measured on thin samples of the bone using a goniometer, and a value for the mean cosine g, of the scattering angle, was calculated. The scattering and absorption coefficients, mu _s and mu _a were then determined from measurements of diffuse reflectance and transmittance made with a pair of integrating spheres, by a step-wise search through a table of diffuse reflectance and transmittance versus mu _a and mu _s generated by a Monte Carlo model incorporating the measured scattering phase function. Values for g measured on six samples varied from 0.925+or-0.014 at 650 nm to 0.945+or-0.013 at 950 nm. Corresponding values for mu _a and mu _s measured on 18 samples were mu _a=0.04+or-0.002 mm^-1s, mu _s=35+or-0.7 mm^-1 at 650 nm to mu _a=0.05+or-0.002 mm^-1, mu _s=24+or-0.6 mm^-1 at 950 nm.