DETECTION OF ACID RAIN POLLUTANTS USING INFRARED LASERS PRODUCED BY STIMULATED ELECTRON RAMAN SCATTERING

THIS PROJECT WILL ESTABLISH THE POTENTIAL FOR RAPID RESPONSE, HIGH RESOLUTION DETECTION AND CHARACTERIZATION OF INFRARED (IR) ACTIVE POLLUTANT MOLECULES, SUCH AS S02, N0, AND N02. MINIATURE OPTICAL HEAT PIPES WILL BE CONSTRUCTED AND OPTIMIZED FOR THE GENERATION OF TUNABLE IR LASER LIGHT BY MEANS OF STIMULATED ELECTRON RAMAN SCATTERING (SERS). THE HEAT PIPES WILL USE ALKALI METAL VAPORS AT PRESSURES ON THE ORDER OF 10 TORR. VISIBLE LIGHT FROM A PULSED TUNABLE DYE LASER WILL PUMP THE ALKALI ATOMS; THESE WILL THEN GENERATE TUNABLE IR LASER LIGHT THROUGH THE SERS PROCESS. IN PHASE I, ABSORPTION MEASUREMENTS ON POLLUTANT MOLECULES CONFINED TO AN ABSORPTION CELL WILL BE PERFORMED TO OPTIMIZE HEAT PIPE DESIGN AND CONSTRUCTION. THE DESIRABILITY OF PROCEEDING IN PHASE II WITH MEASUREMENT OF POLLUTANT MIXTURES BY EITHER SHOT-TO-SHOT, BROAD BAND SERS IR RADIATION, OR TWO-COLOR, RESONANT-RESONANT MULTIPHOTON IONIZATION ALSO WILL BE ASSESSED. SERS-GENERATED PULSED TUNABLE IR LASER BEAMS MAY RESULT IN IMPROVED INSTRUMENTATION IN SUCH AREAS AS REMOTE MEASUREMENTS, LOCALIZED SENSING, AND HIGH SENSITIVITY DETECTION; THEY MAY BE USED IN EXTREME PRESSURE AND/OR TEMPERATURE ENVIRONMENTS.