Optical properties of biological tissues: a review
- Jacques SL
- Phys. Med. Biol. 2013,
The ability of light to penetrate a tissue and deposit energy in tissues is key to therapeutic applications. In this context, the knowledge of the optical properties of the various biological tissues is mandatory, since the efficacy of laser treatment depends on photon propagation and fluence rate distribution within irradiated tissues. Photon propagation in biological tissue is characterized by the basic optical properties of absorption, scattering and refractive index variations. These properties govern the numbers of photons that are transmitted between points on the tissue surface and deep into the tissue. Even for thin, submillimeter sections of tissue, injected photons are likely to be scattered several times before they reach the boundary. As a consequence a coherent, collimated input laser beam will be effectively incoherent and isotropic after traversing a few tissue millimeters, as scattering does not generally preserve coherence.