Fully resonant four-wave mixing spectroscopy of pentacene and dye molecules in condensed phases

Thesis/Dissertation · Tue Jan 01 04:00:00 EST 1985

OSTI ID:6921582

Chang, T C

Four-wave mixing spectroscopy (FWM) including coherent antistokes Raman spectroscopy (CARS) and coherent stokes Raman spectroscopy (CSRS) have been studied for pentacene doped in naphthalene crystals at low temperatures (4.5 to 35 K) in order to investigate nonlinear optical behavior of the third-order nonlinear susceptibility, X/sup (3)/. Further, its application to study of cresyl violet perchlorate embedded in polyacrylic acid and in polyvinyl carbazole has been examined. The theoretical basis for line narrowing has been established for fully resonant four wave mixing for a four-level system. A careful line-narrowing study for the pentacene 755 cm/sup -1/ resonance in naphthalene illustrates that line narrowing is operative. Temperature dependent studies indicate that the excited state population mechanism for negative detuning involves phonon hotband absorption. Power broadening data are discussed in terms of dynamic Stark shifts resulting from the site inhomogeneous line broadening of vibronic transitions. Cresyl violet perchlorate in polyacrylic acid shows that the CARS intensity of the excited state resonance at 585 cm/sup -1/ depends on the location of the omega/sub 1/-field within the severely inhomogeneously broadened absorption profile of the dye. It is argued that the linear electron-phonon interaction is an important mechanism for the intensity of the excited state resonance.

• Research Organization: Iowa State Univ. of Science and Technology, Ames (USA)
• DOE Contract Number: W-7405-ENG-82
• OSTI ID: 6921582
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400500* -- Photochemistry
AROMATICS
CONDENSED AROMATICS
DATA
DYES
EXPERIMENTAL DATA
INFORMATION
LASER SPECTROSCOPY
LINE NARROWING
MULTI-PHOTON PROCESSES
NONLINEAR OPTICS
NUMERICAL DATA
OPTICS
ORGANIC COMPOUNDS
RAMAN SPECTROSCOPY
SPECTROSCOPY
ULTRALOW TEMPERATURE
VERY LOW TEMPERATURE