Raman spectra of biomedical samples using optical fiber probes

We have investigated various optical fiber probes for remote Raman scattering measurements in tissues. The diameter of the optical fiber probe was kept below 3 mm in order to be able to fit into the working channel of existing endoscopes for in vivo measurements inside the human body. Different designs were tested to examine the best possible arrangement of the required optical. The main problems encountered arising from the Raman scattering and fluorescence emission inside the fiber itself are discussed and possible approaches to overcome the limitations are addressed.