Multiple Transient Reflection on Ag Films by Three Pump Beams Heating
X. F. Xu, X. H. Yang, S. Pan, J. B. Li and Y. F. Gao
Ag metal films are deposited by the magnetron sputtering technique. The electron nonequilibrium relaxation process is studied, the time and the number of the electron nonequilibrium relaxation in the Ag films is measured using the femtosecond transient thermal reflection technique. It plays a positive role in solving the problems of the devices which are damaged in the process of the laser heating the metals. The results show that under the multiple pulses heating, the transient reflectivity curves (ΔR/R curves) emerge several sharply rising peaks, and the times of the excitation and the duration of the electron equilibrium relaxation depend of both the thickness and the femtosecond laser pump pulse power.
Keywords: Femtosecond laser, silver film, Ag film, laser heating, nonequilibrium relaxation, transient thermal reflection