Research on stimulated Raman scattering with applications to atmospheric lidar

Research has been conducted on stimulated Raman scattering (SRS) to extend conventional lasers into the infrared where lidar systems can make important contributions to observations of the atmosphere. An efficient "Raman shifted" dye laser system was used to generate tunable and narrow band radiation at 760 and 940 nm for differential absorption lidar applications. The requisite tunability and spectral purity of the output is derived from the dye laser input by controlling the Raman cell at pressure below 14 atm. The converted radiation is optimized for different pump focusing geometries. Energy conversion efficiencies of 45% and 37% at 765 and 940 nm, respectively, were obtained. Optical depth measurements and calculations were made at the centers of 25 lines in the P branch of the oxygen A-band in air. The data and theoretical calculations agree, indicating a high spectral purity of the light source. High resolution parameters of water vapor at 940 nm were obtained using this narrow linewidth Raman-shifted dye laser in conjunction with a multi-pass optical absorption call. Optical strengths and Lorentz widths were deduced from the data using a Voigt line profile to numerically correct for finite laser linewidth. Some lines are compared with prior measurements by Giver et al that used a wholly different method. Some lines, which were not covered in Giver's experiments, were compared with Hitran database. The simultaneous generation of several Stokes orders was investigated in H...