Results 171 to 180 of about 409,083 (217)
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Nondestructive testing of microstructures by picosecond ultrasonics
Journal of Nondestructive Evaluation, 1990We describe a new method we have developed which can be used to make ultrasonic measurements with picosecond time resolution, and give examples of its application to the study of the acoustic and mechanical properties of microstructures.
H. -N. Lin, R. J. Stoner, H. J. Maris
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Deep learning-based identification of characteristic regions for picosecond ultrasonics metrology
Measurement, 2023J. Min +6 more
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Picosecond ultrasonic experiments to study phonon solitons
physica status solidi (b), 2004AbstractWe describe experiments to study the propagation of phonon solitons in crystalline solids. A picosecond light pulse is used to generate a short strain pulse. As this pulse propagates, its shape changes as a result of phonon dispersion and elastic non‐linearity. After traveling a sufficient distance, the pulse breaks up into a number of solitons.
H. J. Maris, W. Singhsomroje
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Generation and detection of incoherent phonons in picosecond ultrasonics
Ultrasonics, 2006In picosecond ultrasonics experiments the absorption of a femtosecond laser pulse in a thin metallic transducer is used to generate very short acoustic pulses. These pulses are made of coherent longitudinal waves with a frequency spectrum that can reach 100-200 GHz. The laser pulse absorption gives rise to a heating of the film of a few Kelvin within a
Perrin, Bernard +2 more
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Nanoacoustics: Towards imaging nanostructures using picosecond ultrasonics
The Journal of the Acoustical Society of America, 2006Coherent acoustic phonon pulses with a peak frequency and bandwidth of the order of 100 GHz can be generated by ultrafast optical excitation of a thin metal film on a crystalline substrate. We demonstrate submicron resolution imaging of surface-grown nanostructures using these picosecond ultrasonic pulses.
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Phonon attenuation in amorphous solids studied by picosecond ultrasonics
Physical Review B, 1996We have used a picosecond optical technique to measure the attenuation {alpha} of longitudinal-acoustic phonons in several disordered solids. We find a universal {alpha}{approximately}{nu}{sup 2} behavior for frequencies {nu} up to 320 GHz and for temperatures between 80 and 300 K.
, Morath, , Maris
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Glass transition of nanometric polymer films probed by picosecond ultrasonics.
Ultrasonics, 2021D. Brick +6 more
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Picosecond holographic grating generation of ultrasonic waves
IEEE Journal of Quantum Electronics, 1986The picosecond holographic grating generation and detection of ultrasonic waves are described. Two mechanisms, a heating mechanism and a stimulated Brillouin scattering mechanism, are described. These permit the generation of tunable ultrasonic waves in the MHz to GHz range.
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Microstructural Analysis of Copper Interconnections Using Picosecond Ultrasonics
MRS Proceedings, 2000AbstractWe demonstrate that picosecond ultrasonics provides detailed information on the structure and properties of patterned arrays of copper fine lines used in silicon chip interconnections. In this method, the sample surface is momentarily heated several °C using a pump laser beam, and the transient change in the optical reflectivity is measured by ...
James M.E. Harper +6 more
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Effect of laser pulse duration in picosecond ultrasonics
Journal of Applied Physics, 2006An optical grating has been introduced in a picosecond ultrasonics experiment, in order to vary continuously the duration of the laser beam pulse from 0.1to150ps. The evolution of the measured signal has been observed and analyzed through the comparison with a theoretical approach based on a two-temperature model.
Perton, M. +5 more
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