LONG FIBEROPTIC REMOTE RAMAN PROBE FOR DETECTION AND IDENTIFICATION OF WEAK SCATTERERS

A long-length fiber-optic remote Raman probe that can detect materials (e.g., Fe2O3) that are weak Raman scatterers is described. The 100-m-long probe consists of one excitation and one collection fiber and accessory optics and is < 3 mm in diameter. We used special filters to solve the problems of Raman scattering and luminescence generated in the silica excitation and collection fibers and a liquid-nitrogen-cooled charge-coupled detector to analyze weak Raman signals.