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For elastography measurements, Muthupillai et al. assumed that a displacement of a few hundreds of nanometers should be sufficient to perform shear wave elastography \cite{7569924}. However, displacements of 5 to 20 $\mu$m are usually required, which is slightly higher than the maximum displacement observed here (about 2 $\mu$m in the chicken breast sample). The minimum energy of the laser (532 nm, 10 ns, 50 mJ, 5 mm diameter) used in our experiments to get a shear wave is about ten times higher than the maximum exposure permissible as given by the current American National Standard Institute (Z136.1-2000) for skin \cite{ANSIZ1361}, but is also about fiftyto hundred  times lower than the typical energy used for skin tatoo removal \cite{8352621}. Shear wave frequency in elastography ranges typically between 50 and 500 Hz, with higher frequency meaning better spatial resolution. The experiments demonstrated that these frequencies can be reached, although the mechanism explaining this particular frequency is not clear yet. 
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