Relaxation processes of point defects in vitreous silica from femtosecond to nanoseconds

The authors studied ultrafast relaxation of localized excited states at Ge-related O deficient centers in SiO2 using femtosecond transient-absorption spectroscopy. The relaxation dynamics exhibits a biexponential decay, which the authors ascribe to the departure from the Frank-Condon region of the 1st excited singlet state in 240 fs, followed by cooling in .apprx.10 ps. At later times, a nonexponential relaxation spanning up to 40 ns occurs, which is fitted with an inhomogeneous distribution of nonradiative relaxation rates, following a chi-square distribution with one degree of freedom. This reveals several analogies with phenomena such as neutron reactions, quantum dot blinking, or intramol. vibrational redistribution. (c) 2008 American Institute of Physics.


Published in:
Applied Physics Letters, 93, 10, 102901/1-102901/3
Year:
2008
Keywords:
Note:
CAN 149:520612
73-2
Optical, Electron, and Mass Spectroscopy and Other Related Properties
Dip. di Scienze Fisiche ed Astronomiche,Universita di Palermo,Palermo,Italy.
Journal
0003-6951
written in English.
7440-56-4 (Germanium) Role: MOA (Modifier or additive use), USES (Uses) (relaxation processes of point defects in vitreous silica from femtosecond to nanoseconds); 60676-86-0 Role: PEP (Physical, engineering or chemical process), PRP (Properties), PROC (Process) (relaxation processes of point defects in vitreous silica from femtosecond to nanoseconds)
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 Record created 2009-03-18, last modified 2018-03-17


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