Effect of tissue fluid on accurate determination of the complex refractive index of animal tissue.

We investigate the effect of tissue fluid on the measurement of complex refractive index (RI) of animal tissue. A new model is proposed and verified through experimental results of simulation samples made of glycerol and methyl-red-doped poly(methyl methacrylate). Coupled with polarized optical reflectance measurements performed on several kinds of animal muscle tissues, RIs were resolved using the new model. We find that the tissue fluid existing at the prism-sample interface is unavoidable. We also find that with a change of proportion of the tissue fluid, the RI of muscle tissue can still be measured using the new model.