TY - JOUR
KW - electronic relaxation
KW - laser breakdown
KW - photoelectron spectroscopy
KW - diamond
KW - paper
AU - J Gaudin
AU - G Geoffroy
AU - S Guizard
AU - Olevano V
AU - S Esnouf
AU - SM Klimentov
AU - PA Pivovarov
AU - SV Garnov
AU - Paul Martin
AU - A Belsky
AU - G Petite
AB - We used high order harmonics of a femtosecond titanium-doped sapphire system (pulse duration 25 fs) to realise Ultraviolet Photoelectron Spectroscopy (UPS) measurements on diamond. The UPS spectra were measured for harmonics in the range 13 to 27. We also made ab initio calculations of the electronic lifetime of conduction electrons in the energy range produced in the UPS experiment. Such calculations show that the lifetime suddenly diminishes when the conduction electron energy reaches the plasmon energy, whereas the UPS spectra show evidence in this range of a strong relaxation mechanism with an increased production of low energy secondary electrons. We propose that in this case the electronic relaxation proceeds in two steps: excitation of a plasmon by the high energy electron, the latter decaying into individual electron-hole pairs, as in the case of metals. This process is observed for the first time in an insulator and, on account of its high efficiency, should be introduced in the models of laser breakdown under high intensity.
BT - LASER PHYSICS LETTERS
CY - PO BOX 10 11 61, D-69451 WEINHEIM, GERMANY
DA - JUN
DO - 10.1002/lapl.200510001
M1 - 6
N2 - We used high order harmonics of a femtosecond titanium-doped sapphire system (pulse duration 25 fs) to realise Ultraviolet Photoelectron Spectroscopy (UPS) measurements on diamond. The UPS spectra were measured for harmonics in the range 13 to 27. We also made ab initio calculations of the electronic lifetime of conduction electrons in the energy range produced in the UPS experiment. Such calculations show that the lifetime suddenly diminishes when the conduction electron energy reaches the plasmon energy, whereas the UPS spectra show evidence in this range of a strong relaxation mechanism with an increased production of low energy secondary electrons. We propose that in this case the electronic relaxation proceeds in two steps: excitation of a plasmon by the high energy electron, the latter decaying into individual electron-hole pairs, as in the case of metals. This process is observed for the first time in an insulator and, on account of its high efficiency, should be introduced in the models of laser breakdown under high intensity.
PB - WILEY-V C H VERLAG GMBH
PP - PO BOX 10 11 61, D-69451 WEINHEIM, GERMANY
PY - 2005
SP - 292
EP - 296
T2 - LASER PHYSICS LETTERS
TI - Plasmon channels in the electronic relaxation of diamond under high-order harmonics femtosecond irradiation
UR - http://dx.doi.org/10.1002/lapl.200510001
VL - 2
ER -