ANISOTROPY OF VOLUME-BACKSCATTERED LIGHT

In many measurements used for the determination of optical properties of biological tissues, a detector with a small cone of acceptance is u sed. Therefore a small part of the anisotropically distributed backsca ttered light is detected. We present the results of Monte Carlo calcul ations and study the anisotropy of the direction distribution of volum e-backscattered photons. Close to the source it is impossible to give a general correction factor to relate the measurements to theoretical results. Far from the source, the measured radiation divided by the sq uare of the sine of the accepting angle of the detector is a relativel y good approximation of the radiant exitance at the surface of the sam ple under investigation. We recommend the use of a detector with a lar ge angle of acceptance for these kinds of measurements. (C) 1997 Optic al Society of America.