Accession Number : ADP008275

Title :   Spectral and Temporal Dynamics of Nonequilibrium Phonons in YAG:Pr3+,

Corporate Author : GEORGIA UNIV ATHENS DEPT OF PHYSICS AND ASTRONOMY

Personal Author(s) : Wang, Xiao-jun ; Dennis, W. M.

Report Date : 22 MAY 1992

Pagination or Media Count : 4

Abstract : We have investigated the spectral and temporal dynamics associated with phonon decay in the YAG:Pr3+ system at a range of temperature between 9 and 25 K. Nonequilibrium phonons were generated using defect induced one phonon absorption (DlOPA) of far infrared (FIR) radiation. Phonon detection was achieved optically using a variation of absorption vibronic sideband phonon spectroscopy. Far infrared radiation in the frequency range 30 - 113 cm-1 was generated using a transversely excited atmospheric pressure CO2 laser pumped superradiant cell. This configuration produces 50 ns FIR pulses with single pulse energies in the range 1 - 10 mJ. The optical detection pulses were generated using a YAG:Nd3+ pumped dye laser. The generation and detection beams were incident on the sample in a counterpropagating geometry with the phonon generated fluorescence collected at 90 deg. The sample was mounted in a two stage cold cycle refrigerator allowing the temperature to be varied between 9 and 300 K. The sample temperature was determined optically,

Descriptors :   *DYNAMICS, *PHONONS, *SPECTRA, *PRASEODYMIUM, *YAG LASERS, ABSORPTION, ATMOSPHERICS, BAROMETRIC PRESSURE, CELLS, CONFIGURATIONS, CYCLES, DECAY, DETECTION, DYE LASERS, DYES, FAR INFRARED RADIATION, FLUORESCENCE, FREQUENCY, GEOMETRY, LASERS, OPTICAL DETECTION, PRESSURE, PULSES, RADIATION, SIDEBANDS, SPECTROSCOPY, TEMPERATURE, VARIATIONS, TIME, IONS, EXCITATION, CARBON DIOXIDE, ENERGY, LASER BEAMS.

Subject Categories : Solid State Physics
      Lasers and Masers
      Atomic and Molecular Physics and Spectroscopy

Distribution Statement : APPROVED FOR PUBLIC RELEASE