RAPID MULTIEXCITATION FLUORESCENCE SPECTROSCOPY SYSTEM FOR IN-VIVO TISSUE DIAGNOSIS

We have designed, fabricated, and tested a compact, transportable, exc itation-emission spectrofluorimeter with optical-fiber light delivery and collection for use in rapid analysis of tissues in a clinical sett ing. This system provides up to eleven different excitation wavelength s, permitting collection of all the corresponding emission spectra in approximately 600 ms. It uses a N-2 laser that pumps a sequence of dye s placed in cuvettes on a rotating wheel. A white-light excitation sou rce permits acquisition of the tissue's diffuse reflectance spectrum o n each cycle. Return fluorescence and reflected light are dispersed by a small spectrograph and detected by a photodiode-array detector. The system can celled a single-shot spectrum from biological tissue with a signal-to-noise ratio in excess of 50:1. (C) 1996 Optical Society of America