Depth-sensitive fluorescence spectroscopy in a two-layered epithelial tissue phantom was demonstrated using a cone shell configuration implemented by an axicon lens and a fiber assembly including five rings of collection fibers. Each collection fiber ring was located at a different radial distance away from the center, for which fluorescence measurements from all rings showed a larger range of sensitivities to the top and bottom layers compared to the previously reported cone shell configuration. Furthermore, multiple fluorescence spectra corresponding to a range of successive targeted depths can be obtained simultaneously, which shortened data acquisition dramatically and eliminated the mechanical moving components required for depth-sensitive optical measurements in the previous setup. This new setup therefore would be preferred in a clinical setting.

MOE (Min. of Education, S’pore)

NMRC (Natl Medical Research Council, S’pore)