ISSN:
1432-0630
Schlagwort(e):
142.65.Ky
;
63.20.Kr
;
78.47.+p
Quelle:
Springer Online Journal Archives 1860-2000
Thema:
Maschinenbau
,
Physik
Notizen:
Abstract Optical Second-Harmonic Generation (SHG) in reflection from a polycrystalline copper surface in air was studied using femtosecond time-resolved pump and probe measurements at λ=625 nm. The observed time dependence of second-harmonic yield from the probe beam demonstrates, that SHG is a very sensitive technique for measuring transient electron temperatures of metals even when these are covered by an oxide layer. For polycrystalline copper, an electron-phonon energy transfer time of 2 ps was observed, corresponding to a coupling constant of 3.75×1017 W/m3 K at average lattice temperatures of about 500 K. The analysis of experimental data indicates that the time dependence of SHG is governed by the linear dielectric function ε which, in turn, is affected by the electron temperature. There is no evidence for a temperature dependence of the nonlinear susceptibility χ(2).
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1007/BF01538238
