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In a context of shear wave elastography, the thermoelastic regime is a priori preferred to the ablative regime, as it is less destructive. If Muthupillai et al. assumed that a displacement of a few hundreds of nanometers should be sufficient to perform shear wave elastography \cite{7569924}, displacements of the order of the micrometer are usually required in ultrasound or MRI elastography: this is higher than the displacement observed at 10 mJ (thermoelastic regime) and about the same order of magnitude at 200 mJ (ablative regime). The minimum energy (10 mJ) of the laser beam used in our experiments is incidentally 2.5 times above the maximum exposure permissible for skin given by the Z136.1-2007 standard of the American National Standard Institute \cite{ANSIZ1361}. In a practical application in the human body, different strategies could be adopted to comply to ANSI standard: observe the medium with high resolution imaging technique, able to track displacements of a few nanometers, like high frequency ~(\~100 (\~ 100  MHz) ultrasound imaging, or Optical Coherence Tomography technique as done by Li et al. \cite{Li_2011}; or emit the laser beam on a protective absorbing layer, for example a black sheet sticked to the patient organ. To sum up this article, we have presented experimental observations in soft medium of elastic shear waves generated by a laser beam. The involved phenomenons were investigated and we distinguished thermoelastic and ablative regimes. Theoretical displacements were in good agreement to experimental measurements. Numerical studies showed comparable displacement propagation patterns as experimental ones.