Plasmon channels in the electronic relaxation of diamond under high-order harmonics femtosecond irradiation
|Title||Plasmon channels in the electronic relaxation of diamond under high-order harmonics femtosecond irradiation|
|Publication Type||Palaiseau Article|
|Author Address|| |
Petite, G (Reprint Author), CNRS SPM, CEA DSM, UMR 7642, Solides Irradies Lab, F-91128 Palaiseau, France. CNRS SPM, CEA DSM, UMR 7642, Solides Irradies Lab, F-91128 Palaiseau, France. Ecole Polytech, F-91128 Palaiseau, France. RAS, Inst Gen Phys, Moscow 119191, Russia. Univ Bordeaux 1, Lab CELIA, UMR 5107, F-33405 Talence, France.
|Gaudin, J, Geoffroy, G, Guizard, S, Olevano, V, Esnouf, S, Klimentov, SM, Pivovarov, PA, Garnov, SV, Martin, PC, Belsky, A, Petite, G|
|Year of Publication||2005|
|Journal||LASER PHYSICS LETTERS|
|Keywords||electronic relaxation; laser breakdown; photoelectron spectroscopy; diamond, paper|
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.