We present what is to our knowledge the first experimental study of light-induced reflectivity changes at an α-Ga/Si interface irradiated by femtosecond and picosecond laser pulses. After exposure, the reflectivity can increase from R≊0.55 , which is typical for α-Ga , to R≊0.8 , which is close to that of liquid Ga. The initial step in the reflectivity change of 2–4 ps is resolved with 150-fs laser pulses. The light-induced reflectivity change relaxes during 100ns–10 μs , depending strongly on the background temperature of the Ga mirror and the laser fluence.
© 2001 Optical Society of America
(160.3900) Materials : Metals
(190.4350) Nonlinear optics : Nonlinear optics at surfaces
(190.7110) Nonlinear optics : Ultrafast nonlinear optics
(240.4350) Optics at surfaces : Nonlinear optics at surfaces
(320.7130) Ultrafast optics : Ultrafast processes in condensed matter, including semiconductors
A. V. Rode, M. Samoc, B. Luther-Davies, E. G. Gamaly, K. F. MacDonald, and N. I. Zheludev, "Dynamics of light-induced reflectivity switching in gallium films deposited on silica by pulsed laser ablation," Opt. Lett. 26, 441-443 (2001)