Abstract

The wide development of lasers in medicine and surgery has increased the interest of studying propagation of light in mammalian tissues. Since few and contrasting data about optical parameters of human tissue have been reported, our aim was to add further information by directly measuring extinction and absorption coefficients and a single scattering diagram. Thin sections, from 0.05 to 0.2 mm thick, of various human tissues were cut with a microtome from frozen samples. The slices, after having been hydrated with saline, were placed between two optical grade glasses and sealed. The extinction coefficient was evaluated by measuring the light, delivered through an optical fiber from an argon-dye laser, transmitted on-axis and within 2 × 10⁻⁵ sr. The absorption coefficient was measured by placing a specimen into an integrating sphere. The scattering coefficient was evaluated by the difference between extinction and absorption. The scattering diagram was evaluated by positioning a specimen in a cylindric tank filled with saline. Light scattered within 25 mrad was measured at different angles. The following table shows the values of scattering s and absorption a coefficients and the average cosine of scattering g for various tissues at 635-nm wavelength.

© 1988 Optical Society of America