Optical property measurements of turbid media using continuous-wave light sources

Both the integrating sphere (IS) method and the diffuse video reflectometry (VR) method are used to measure the optical properties of turbid media, and the results are compared. Target samples are made using absorbers and scatterers of known optical properties mixed with pure water. The VR method measures the absorption coefficient with high accuracy even when the absorption coefficient is as low as that of water. On the other hand, the IS method significantly overestimates the absorption coefficient depending on the optical penetration depth. The IS method seems to estimate the scattering coefficient with better accuracy than the VR method does. The results show that the IS method has to be used with much care, especially when the absorption coefficient is low and the penetration depth is high.