The optical properties of a rat muscle and myocardium were measured at two wavelengths 980 and 1860 nm. The tissues used in this experiment were fresh and sliced to a specific thickness of 600 μm. A single integrating sphere system was used to determine the diffuse reflectance, diffuse transmittance, and collimated transmittance of these tissue samples. An inverse Monte Carlo algorithm was then used to calculate the optical properties from the measurements obtained from the single integrating sphere system.

We measured the reduced scattering coefficient and absorption coefficient of biological tissues of rats for 980nm and 1863nm. Results suggest potential presence of a chromophore other than water that absorbs infrared radiation in tissues.