Optimized optical generation and detection of superlattice acoustic phonons

M.F. Pascual Winter (1) , A. Fainstein (2, 3) , Bernard Jusserand (1) , Bernard Perrin (1) , A. Lemaitre

1 INSP - Institut des Nanosciences de Paris
2 Centro Atómico Bariloche [Argentine]
3 Instituto Balseiro [Bariloche]

We present a device for the optimization of the folded acoustic phonon signal in femtosecond pump-probe experiments through the spatial decoupling of the generation and detection processes in two different GaAs/AlAs superlattices separated by a thick GaAs layer. A thickness gradient in one of them allows a fine tuning of the generation and detection spectral responses. In the optimal overlap condition, a clear enhancement of the signal is observed at a time delay that matches the travel time of acoustic phonons through the intermediate layer. This nanostructure provides a sensitive tool for studying terahertz phonon propagation over long distances.

Mots clés: aluminium compounds; gallium compounds; high-speed optical techniques; III-V semiconductors; phonons; semiconductor superlattices

Domaines: Acoustique [physics.class-ph]; Acoustique [physics.class-ph]

M.F. Pascual Winter, A. Fainstein, Bernard Jusserand, Bernard Perrin, A. Lemaitre. Optimized optical generation and detection of superlattice acoustic phonons. Applied Physics Letters, 2009, 94 (10), pp.103103. ⟨10.1063/1.3097244⟩. ⟨hal-00418653⟩