Modification of coherent acoustic phonon lifetimes in thin gold films by self-assembled molecular monolayers

M. HETTICH; A. BRUCHHAUSEN; S. RIEDEL; S. VERLEGER; T. GELDHAUSER; R. CHAUHAN; O. RISTOW; D. ISSENMANN; J. BONEBERG; P. LEIDERER; E. SCHEER; J. DUAL; T. DEKORSY

Munich

Conferencia; The European Conference on Lasers and Electro-Optics and the XIIth European Quantum Electronics Conference (CLEO®/Europe-EQEC 2011)(CLEO/EQEC 2011)); 2011

European Physical Society

We report on the modification of coherent acoustic phonon lifetimes in thin gold films induced by insertion of self-assembled monolayers as interface layers between gold films and substrates. The lifetimes of coherentacoustic phonons are investigated by asynchronous optical sampling (ASOPS), a high speed pump-probe method which utilizes two Ti:sapphire lasers of ~1 GHz repetition rate. The time delay between pump and probe pulse is obtained by a repetition rate offset of 5 kHz. The absence of moving mechanical parts allows for fast scanning times and high signal to noise ratios which are hard to achieve by conventional pump-probe methods.