Distance insensitive reflectance setup for the spectrally resolved determination of the optical properties of highly turbid media.

Abstract

A measurement system for a distance insensitive acquisition of the reflectance from turbid media is presented. The geometric relationships of the detection unit are discussed theoretically and subsequently verified using Monte Carlo simulations. In addition, an experimental setup is presented to prove the theoretical considerations and simulations. The use of the presented measurement system allows measurements of the reflectance in a distance range of approximately 2.5cm with a deviation of less than ±0.5% for highly scattering media. This contrasts with the use of a fiber in a classical detection unit placed at a defined angle and position relative to the sample surface, which results in deviations of ±30% in the measured reflectance over the same distance range.