Experimental proof of the feasibility of using an angled fiber-optic probe for depth-sensitive fluorescence spectroscopy of turbid media.

An angled fiber-optic probe that facilitates depth-sensitive fluorescence measurements was developed for enhancing detection of epithelial precancers. The probe was tested on solid, two-layered phantoms and proved to be effective in selectively detecting fluorescence from different layers. Specifically, a larger illumination angle provides greater sensitivity to fluorescence from the top layer as well as yielding an overall higher fluorescence signal. Monte Carlo simulations of a theoretical model of the phantoms demonstrate that increasing the illumination angle results in an increased excitation photon density and, thus, in increased fluorescence generated in the top layer.