Publisher’s Note: Imaging Ripples on Phononic Crystals Reveals Acoustic Band Structure and Bloch Harmonics [Phys. Rev. Lett.97, 055502 (2006)]

Influence of residual disorder on the anticrossing of Bloch modes probed inkspace

“…Since the investigations of waves propagating in a periodic medium by Lord Rayleigh in 1887, 1 the topic has played a crucial role in a large number of fields such as solid-state physics, 2 acoustic physics, 3 semiconductor superlattices, 4 integrated optics, 5 and photonic lattices. 6 One of the basic properties associated with periodic structures is the existence of frequency band gaps, which are widely used to engineer the propagation of waves.…”

Spatial-temporally resolved high-frequency surface acoustic waves on silicon investigated by femtosecond spectroscopy

“…We attribute these modes to so called LLSAW that have a dominant longitudinal component and are attenuated mostly because of the emission of bulk shear waves. 14,23,24 The calculated mode patterns for the LLSAW show clear signs of this longitudinal character of the wave (along the surface polarization).…”

“…Instead of measuring surface displacement, we detect the change in optical reflectivity due to the strain created by the waves. While other methods have been used to completely map the acoustic band structure of SAWs such as Rayleigh-like waves (RSAW) and leaky longitudinal SAWs (LLSAW), 14 no measurements at such high frequencies have been performed so far that were able to spatially and temporally map these modes.…”

Optical generation of surface acoustic waves guided at the linear boundary between two thin films

“…Recently, laser-generated SAWs in patterned thin film microstructures comprised of different materials have also attracted attention. [3][4][5][6] This activity is stimulated by the proliferation of photoacoustic techniques in process control applications in silicon microelectronics, 7,8 where patterned thin film structures play a crucial role.…”