Coherent backscattering spectroscopy: a new technique for tissue diagnosis

Coherent backscattering (CBS) is a photon weak-localization phenomenon that gives rise to an enhanced backscattering of light by random media. This effect has been previously investigated using coherent light sources. Here we show that CBS can be observed using broadband low-coherence light. We demonstrate, for the first time to the best of our knowledge, that low-coherence detection substantially simplifies CBS measurements in biological tissue and enables depth-resolved spectroscopic analysis of CBS. CBS spectroscopy may find important applications in probing random media such as biological tissues where depth-selective measurements are crucial.