Accession Number : ADA302765

Title :   Applications of Free-Electron Lasers to Measurements of Energy Transfer in Biopolymers and Materials.

Descriptive Note : Rept. 1 Feb 87-31 Jan 91,

Corporate Author : VANDERBILT UNIV NASHVILLE TN DEPT OF PHYSICS AND ASTRONOMY

Personal Author(s) : Edwards, Glenn ; Johnson, Bruce ; Kozub, John ; Tribble, Jerri ; Wagner, Katrina

PDF Url : ADA302765

Report Date : 1991

Pagination or Media Count : 12

Abstract : Free-electron lasers (FELs) provide tunable, pulsed radiation in the infrared. Using the FEL as a pump beam, we are investigating the mechanisms for energy transfer between localized vibrational modes and between vibrational modes and lattice or phonon modes. Either a laser-Raman system or a Fourier transform infrared (FFIR) spectrometer will serve as the probe beam, with the attribute of placing the burden of detection on two conventional spectroscopic techniques that circumvent the lirnited response of infrared detectors. More specifically, the Raman effect inelastic ally shifts an exciting laser line, typically a visible frequency, by the energy of the vibrational mode; however, the shifted Raman lines also lie in the visible, allowing for detection with highly efficient visible detectors. With regards to FTlR spectroscopy, the multiplex advantage yields a distinct benefit for infrared detector response. Our group is investigating intramolecular and intermolecular energy transfer processes in both biopolymers and more traditional materials. For example, alkali halides contain a number of defect types that effectively transfer energy in an intermolecular process. Similarly, the functioning of biopolymers depends on efficient intramolecular energy transfer. Understanding these mechanisms will enhance our ability to modify biopolymers and materials with applications to biology, medicine, and materials science.

Descriptors :   *VIBRATION, *PULSED LASERS, *FREE ELECTRON LASERS, *INFRARED RADIATION, *RAMAN SPECTRA, FOURIER TRANSFORMATION, FREQUENCY, PROBES, RADIATION, DETECTION, DETECTORS, BIOLOGY, SPECTROSCOPY, MATERIALS, POLYMERS, EFFICIENCY, ENERGY TRANSFER, LASERS, MEDICINE, PULSES, RESPONSE, ORGANIC MATERIALS, VISIBILITY, HALIDES, INFRARED DETECTORS, MOLECULE MOLECULE INTERACTIONS, PHONONS, PUMPS, MOLECULAR PROPERTIES, SPECTROMETERS, ALKALI METAL COMPOUNDS.

Subject Categories : Inorganic Chemistry
      Lasers and Masers
      Atomic and Molecular Physics and Spectroscopy

Distribution Statement : APPROVED FOR PUBLIC RELEASE