Measurement of optical properties of biological tissues by low-coherence reflectometry

TLDR

The authors use a first‑order scattering theory to relate backscattered power to scatterer cross sections, validating the approach with a commercial reflectometer on polystyrene microsphere suspensions. The study demonstrates that low‑coherence reflectometry can determine optical properties of dense tissues, probing skin to nearly 1 mm depth with a 1300‑nm LED source and providing optical coefficient estimates for human dermis and various animal tissues.

Abstract

We show that optical properties of dense biological tissues can be determined from backscattered power curves measured by a low-coherence reflectometer. Our measurement approach is based on a first-order scattering theory that relates the backscattered power to the total and backscattering cross sections of scatterers in a turbid medium. As a validation of the technique, measurements were made with a commercially available reflectometer on suspensions of polystyrene microspheres having known optical properties. With this reflectometer, which employs a 1300-nm LED source that emits less than 20 µW, we found that skin tissues could be probed to a depth of nearly 1 mm. Estimates of optical coefficients of human dermis and of a variety of excised animal tissues are given.