THE SLOWING-DOWN OF ULTRAFAST RELAXATION IN C-60 FILMS AT HIGH FEMTOSECOND PUMP INTENSITIES

Authors
FARZTDINOV VM KOVALENKO SA MATVEETS YA STARODUBTSEV NF MAROWSKY G
Citation
Vm. Farztdinov et al., THE SLOWING-DOWN OF ULTRAFAST RELAXATION IN C-60 FILMS AT HIGH FEMTOSECOND PUMP INTENSITIES, Applied physics. B, Lasers and optics, 66(2), 1998, pp. 225-230
Citations number
34
Categorie Soggetti
Physics, Applied",Optics
Journal title
Applied physics. B, Lasers and optics → ACNP
ISSN journal
09462171
Volume
66
Issue
2
Year of publication
1998
Pages
225 - 230
Database
ISI
SICI code
0946-2171(1998)66:2<225:TSOURI>2.0.ZU;2-N
Abstract
The ultrafast relaxation after excitation of a C-60 thin film was inve stigated in the energy range between 1.6 eV and 3.4 eV by a pump-super continuum probe (PSCP) technique with a 40 fs time resolution. The rel axation rate showed pronounced spectral dependence, with a maximum at 2 eV in the region of photo-induced darkening and at 2.4 eV in the reg ion of photo-induced bleaching. The ultrafast relaxation rate decrease d with increasing pump-pulse intensity, We suggest that the observed d ecrease results from extraheating of the carriers in the h(u) and t(lu ) bands due to internal conversion from higher excited states, which a re populated by two-step photon absorption of the intense pump pulse.