Effects of absorption on coherence domain path length resolved dynamic light scattering in the diffuse regime

A low coherence Mach–Zehnder interferometer is developed for path length resolved dynamic light scattering in highly turbid media. The path length distribution of multiply scattered photons in Intralipid is changed by the addition of absorbing dyes. Path length distributions obtained for various absorption levels are shown to be mutually related by Lambert–Beer’s law. Furthermore, the broadening of path length resolved heterodyne light beating spectra of media with identical scattering properties is shown to be independent of the absorption coefficient.