DEVELOPMENT OF A COMPACT RAMAN SPECTROSCOPY SYSTEM FOR CHEMICAL CONTAMINATION MONITORING

CHROMEX HAS DEMONSTRATED CCD ARRAY DETECTOR-BASED RAMAN SPECTROSCOPY EMPLOYING LASER DIODES AND OPTICAL FIBER PROBES CAPABLE OF SENSITIVITIES COMPARABLE TO OR BETTER THAN THE FOURIER TRANSFORM RAMAN (FTR) METHOD. IT IS LIKELY THIS NEW METHOD CAN BE IMPLEMENTED IN A RUGGED COMPACT INSTRUMENT HAVING NO MOVING PARTS, IN A PACKAGE OF LESS THAN 1 FT.3, WEIGHING LESS THAN 50 POUNDS, AND REQUIRING LESS THAN 100 WATTS OF POWER INCLUDING THE LASER AND COOLED CCD. USING AN IMPROVED VERSION OF AN EXISTING 100MM IMAGING SPECTROGRAPH DESIGN, CHROMEX HEREIN PROPOSES A COMPACT CCD ARRAY DETECTOR-BASED RAMAN INSTRUMENT DESIGN THAT, BECAUSE OF ITS HIGH EFFICIENCY OPTICAL FIBER RAMAN PROBE, HIGH THROUGHPUT (F/2), AND IMAGING CAPABILITY (LIMITING THE NUMBER OF REQUIRED VERTICAL PIXELS, HENCE, NOISE), WILL IMPROVE SIGNAL-TO-NOISE BY AT LEAST AN ORDER OF MAGNITUDE COMPARED TO CONVENTIONAL INSTRUMENTS EMPLOYING CCD ARRAY DETECTORS. THIS SYSTEM WILL BE CAPABLE OF OBTAINING SIGNATURES FROM RAMAN SCATTERERS IN FRACTIONS OF A SECOND. THIS PROPOSAL DEVELOPS THEORETICAL ARGUMENTS SUPPORTED BY EXPERIMENTAL RESULTS WHICH SHOW THAT IS REASONABLE TO ANTICIPATE A COMPACT, EVEN PORTABLE, RAMAN SYSTEM CAPABLE OF CONVENIENT AND RAPID DETECTION OF LIQUID AND SOLID CONTAMINANTS ON SURFACES AT COVERAGES OF 1 GRAM/METER2.