Patent ID: 6621574
Filing Date: 2003-09-16
Classification: G01J,G01N

Abstract:
An assembly for obtaining calibrated Raman spectra over optical fibers and for ensuring eye safety said assembly comprising:a) a Raman sampling probe at the terminus of optical fibers for conducting monochromatic light to a sample and/or for returning light scattered off the sample to a spectrograph, said monochromatic light exiting the distal end of the probe, illuminating the sample, and the light scattered from the sample also collected at the distal end of the probe in a backscattering geometry, and b) a moveable aperture in the optical path between the distal end of the sampling probe and the sample with at least two mechanically interchangeable positions: a first position containing an opening or transmissive optical element permitting the monochromatic light to illuminate the sample and backscattered light to be collected by the probe and returned to the spectrograph to produce a sample spectrum, and a second position blocking light to the sample and to the eye and further placing in the optical path an optical standard that delivers to the probe a standard spectrum which is returned to the spectrograph for instrument calibration.