skip to main content

SciTech ConnectSciTech Connect

Title: Real-time observation of coherent acoustic phonons generated by an acoustically mismatched optoacoustic transducer using x-ray diffraction

The spectrum of laser-generated acoustic phonons in indium antimonide coated with a thin nickel film has been studied using time-resolved x-ray diffraction. Strain pulses that can be considered to be built up from coherent phonons were generated in the nickel film by absorption of short laser pulses. Acoustic reflections at the Ni–InSb interface leads to interference that strongly modifies the resulting phonon spectrum. The study was performed with high momentum transfer resolution together with high time resolution. This was achieved by using a third-generation synchrotron radiation source that provided a high-brightness beam and an ultrafast x-ray streak camera to obtain a temporal resolution of 10 ps. We also carried out simulations, using commercial finite element software packages and on-line dynamic diffraction tools. Using these tools, it is possible to calculate the time-resolved x-ray reflectivity from these complicated strain shapes. The acoustic pulses have a peak strain amplitude close to 1%, and we investigated the possibility to use this device as an x-ray switch. At a bright source optimized for hard x-ray generation, the low reflectivity may be an acceptable trade-off to obtain a pulse duration that is more than an order of magnitude shorter.
Authors:
;  [1] ; ;  [2] ;  [1] ;  [3]
  1. Department of Physics, Lund University, P.O. Box 118, SE-221 00 Lund (Sweden)
  2. MAX IV Laboratory, Lund University, P.O. Box 118, SE-221 00 Lund (Sweden)
  3. (Sweden)
Publication Date:
OSTI Identifier:
22492927
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 118; Journal Issue: 18; Other Information: (c) 2015 Author(s); Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; ABSORPTION; BRIGHTNESS; FILMS; FINITE ELEMENT METHOD; HARD X RADIATION; INDIUM ANTIMONIDES; NICKEL; PHONONS; PULSES; REFLECTIVITY; STREAK CAMERAS; SWITCHES; TIME RESOLUTION; X-RAY DIFFRACTION