MEASUREMENT OF OPTICAL-PROPERTIES OF BIOLOGICAL TISSUES BY LOW-COHERENCE REFLECTOMETRY

We show that optical properties of dense biological tissues can be det ermined from backscattered power curves measured by a low-coherence re flectometer. Our measurement approach is based on a first-order scatte ring theory that relates the backscattered power to the total and back scattering cross sections of scatterers in a turbid medium. As a valid ation of the technique, measurements were made with a commercially ava ilable reflectometer on suspensions of polystyrene microspheres having known optical properties. With this reflectometer, which employs a 13 00-nm LED source that emits less than 20 muW, we found that skin tissu es could be probed to a depth of nearly 1 mm. Estimates of optical coe fficients of human dermis and of a variety of excised animal tissues a re given.