Results 131 to 140 of about 1,507 (165)
Solitary surface acoustic waves and bulk solitons in nanosecond and picosecond laser ultrasonics
Ultrasonics, 2010 Recent achievements of nonlinear acoustics concerning the realization of solitons and solitary waves in crystals and their surfaces attained by nanosecond and picosecond laser ultrasonics are discussed and compared. The corresponding pump-probe setups are described, which allow an all-optical contact-free excitation and detection of short strain pulses
Peter, Hess, Alexey M, Lomonosov
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The European Physical Journal Special Topics, 2008 Picosecond laser ultrasonics uses femtosecond laser pulses for the generation and detection of acoustic pulses with a typical duration between few picoseconds and few hundreds of pico seconds. The shorter the duration of the acoustic pulse is, the more precisely could be made the measurements of the film thickness [C. Thomsen et al., Phys. Rev.
C. Mechri +7 more
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The Journal of the Acoustical Society of America, 2011 Research results on the characterization of the thin (submicrometers thick) films of the nanostructured materials by the experimental methods of picosecond laser ultrasonics are reviewed. These methods make use of femtosecond lasers to generate and to detect GHz–THz acoustic waves.
V. Gusev, P. Ruello
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Phonons rectification in picosecond laser ultrasonics
The Journal of the Acoustical Society of America, 2008 In standard ultrafast acoustic experiments very short coherent acoustic pulses are generated by the absorption of a femtosecond laser pulse in a thin metallic transducer deposited on the sample. Subsequently the acoustic pulses and the heat generated in the transducer cross the sample and are partially transmitted in the underlaying substrate.
Bernard Perrin +3 more
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Journal of Applied Physics, 1999 This article describes the use of optical methods based on picosecond transient gratings to stimulate and detect ultrasonic acoustic modes in several important structures with dimensions less than ∼200 μm: single-mode optical fiber, cylindrical microcapillary tubes, and planar microfluidic networks.
John A. Rogers
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Imaging of 3D acoustic wave-fronts by means of picosecond laser ultrasonics in GaAs substrate
The Journal of the Acoustical Society of America, 2008 Picosecond ultrasonic experiments are widely used as pump-probe technique using longitudinal acoustic pulses and measuring time dependence of the signal. We present an experiment which combines an interferometer with the control of the pump-probe spatial overlap.
Emmanuel Péronne +4 more
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Sensitive detection of laser damage to Mo/Si multilayers by picosecond ultrasonics
Applied Physics B, 2004 Picosecond ultrasonics is used to study the damage or degradation of Mo/Si multilayers caused by laser irradiation. Changes of surface phonon spectra in multilayers due to femtosecond laser damaging are observed in a regime of extremely low fluence level, well before the onset of melting, delamination, distortion, or material interdiffusion.
N.-W. Pu, E.-Y. Pan, J. Bokor
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IEEE Symposium on Ultrasonics, 2003, 2004 In this paper, the effects of the laser pulse duration (100 fs - 12 ps) are investigated on the generation and the detection of photo-acoustic signals. A model of generation and detection of ultrasonic waves with ultra-shorts laser pulses is presented.
Rossignol, C. +4 more
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LASER PICOSECOND ULTRASONIC MEASUREMENT OF LONGITUDINAL SOUND VELOCITY IN NANOMETER THIN FILMS
AIP Conference Proceedings, 2008 We demonstrate applications of ultrafast‐laser‐based picosecond ultrasonic techniques to sound velocity measurement in nanometer thin films. The longitudinal sound velocities in various thin films (100∼300 nm thick) were directly determined by pulse‐echo technique.
N. W. Pu +3 more
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