Recent reports indicate that useful diagnostic information can be obtained
from ex vivo tissue by using near-infrared Raman spectroscopy. A fiber-opti
c-based Raman system has been constructed that can obtain spectra in vivo f
rom tissue, typically in less than 30 s. The spectral details are limited b
y the fluorescence and Raman signal generated in the silica delivery and co
llection fibers. In this study, fiber-optic probes that are designed to sup
press these confounding signals have been characterized and compared with a
probe constructed of unfiltered silica fiber. These suppressing probes use
d a novel design with "in-the-tip" filters, which also had optimized light
collection efficiency. The spatial point response functions of the fibers w
ere measured in air, water, and a tissue-simulating, optically turbid mediu
m. Spectra from rabbit tissues were also collected with these probes to dem
onstrate their performance.