Detection of shorter-than-skin-depth acoustic pulses in a metal film via transient reflectivity

Abstract

The detection of ultrashort laser-generated acoustic pulses at a metal surface and the reconstruction of the acoustic strain profile are investigated. A 2 ps-long acoustic pulse generated in an SrRuO${}_3$ layer propagates through an adjacent gold layer and is detected at its surface by a reflected probe pulse. We show that the intricate shape of the transient reflectivity waveform and the ability to resolve acoustic pulses shorter than the optical skin depth are controlled by a single parameter, which is determined by the ratio of the real and imaginary parts of the photoelastic constant of the material. We also demonstrate a Fourier transform-based algorithm that can be used to extract acoustic strain profiles from transient reflectivity measurements.

References in corpus (2)

• The marriage of plasmonics, magnetism, acoustics and ultrafast optics
• Femtosecond nonlinear ultrasonics in gold probed with ultrashort surface plasmons

Cited by in corpus (4)

• Nonlinear acousto-magneto-plasmonics
• Generation of exchange magnons in thin ferromagnetic films by ultrashort acoustic pulses
• Magnetically-tunable cutoff in asymmetric thin metal film plasmonic waveguide
• Anomalous frequency scaling of acoustic phonon damping in nickel cavities fabricated by ps-laser delamination