REMOTE RAMAN MICROIMAGING USING AN AOTF AND A SPATIALLY COHERENT MICROFIBER OPTICAL PROBE

A fiber-optic Raman microimaging probe is described that is suitable f or acquiring high-spatial-resolution Raman images in sampling situatio ns with no clear line of sight. A high-power near-infrared diode laser combined with an acousto-optic tunable filter and a spatially coheren t optical fiber bundle allow fluorescence-free Raman images of remotel y located samples to be acquired at distances up to several meters. Th e feasibility of this technique is demonstrated with Raman images of ( 1) a pellet containing a mixture of a highly scattering sample, bis-me thylstyrylbenzene (BMSB), KCl, and graphite, and (2) a partially graph itized diamond. These images clearly show phase boundaries over an are a of approximately 0.1 mm(2) with similar to 4-mu m resolution.