Sound velocity mapping from GHz Brillouin oscillations in transparent materials by optical incidence from the side of the sample
Abstract
Time-domain Brillouin scattering (TDBS) is an all-optical experimental technique for investigating transparent materials based on laser picosecond ultrasonics. Its application ranges from imaging thin-films, polycrystalline materials and biological cells to physical properties such as residual stress, temperature gradients and nonlinear coherent nano-acoustic pulses. When the sample refractive index is spatially uniform and known in TDBS, analysis by windowed Fourier transforms allows one to depth-profile the sound velocity. Here, we present a new method in TDBS for extracting sound velocity without a knowledge of the refractive index, by use of probe light obliquely incident on a side face-as opposed to the usual top face-of the sample. We demonstrate this method using a fused silica sample with a titanium transducer film and map the sound velocity in the depth direction. In future, it should be possible to map the sound velocity distribution in three dimensions in inhomogeneous samples, with applications to the imaging of biological cells.
Related
- Translation and discussion of Leon Brillouin's 1922 paper titled: Diffusion of light and X-rays by a transparent homogeneous body: influence of thermal agitation
- Short-pulse stimulated Brillouin scattering threshold in lossy waveguides
- Recovery of event boundaries and Brillouin frequency shift in STFT-BOTDR using variable projection with spatial response constraint
- Elastic constants of congruent and nearly stoichiometric lithium niobate crystals by Brillouin light scattering up to 800 °C
- Synergy and reciprocity between Brillouin and Mie scattering by the presence of silver nanoparticles in the stimulated Brillouin scattering cell
BibTeX
@article{tomoda2026sound,
title = {{Sound velocity mapping from GHz Brillouin oscillations in transparent materials by optical incidence from the side of the sample}},
author = {Motonobu Tomoda and Akira Toda and Osamu Matsuda and Vitalyi Gusev and Oliver Wright},
journal = {Photoacoustics},
year = {2026},
month = oct,
doi = {10.1016/j.pacs.2023.100459},
url = {https://hal.science/hal-05779050v1},
note = {CC BY-NC-ND},
}
RIS
TY - JOUR
TI - Sound velocity mapping from GHz Brillouin oscillations in transparent materials by optical incidence from the side of the sample
AU - Motonobu Tomoda
AU - Akira Toda
AU - Osamu Matsuda
AU - Vitalyi Gusev
AU - Oliver Wright
PY - 2026
DA - 2026/10/05
JO - Photoacoustics
DO - 10.1016/j.pacs.2023.100459
UR - https://hal.science/hal-05779050v1
AB - Time-domain Brillouin scattering (TDBS) is an all-optical experimental technique for investigating transparent materials based on laser picosecond ultrasonics. Its application ranges from imaging thin-films, polycrystalline materials and biological cells to physical properties such as residual stress, temperature gradients and nonlinear coherent nano-acoustic pulses. When the sample refractive index is spatially uniform and known in TDBS, analysis by windowed Fourier transforms allows one to depth-profile the sound velocity. Here, we present a new method in TDBS for extracting sound velocity without a knowledge of the refractive index, by use of probe light obliquely incident on a side face-as opposed to the usual top face-of the sample. We demonstrate this method using a fused silica sample with a titanium transducer film and map the sound velocity in the depth direction. In future, it should be possible to map the sound velocity distribution in three dimensions in inhomogeneous samples, with applications to the imaging of biological cells.
SN - 2213-5979
ER -