Anisotropic optical property of a bio-medium with highly photon-scattering anisotropic bio-molecules

Tissues are optically anisotropic and highly photon scattering media. By using a simple ellipsoid model of bio-molecules with anisotropic distribution and using an effective mean-field theory, the principal anisotropic index of refraction n(j)(omega) and absorption extinction coefficient kappa(aj)(omega), (j = x,y,z) are derived. The scattering extinction coefficient kappa(sj) is calculated from our scattering depolarization theory of highly scattering bio-medium. The criterion of optical isotropy and anisotropy of a bio-medium is derived. The non-vanishing Delta n, Delta kappa(a) and Delta kappa(s) exist for medium with anisotropic molecules only. Delta kappa(s)/ is larger for medium with higher density.