Transient time-delay focusing of shock waves in thin liquids
Por:
Gutierrez-Hernandez, Ulisses J., De Colle, Fabio, Ohl, Claus-Dieter, Quinto-Su, Pedro A.
Publicada:
13 ene 2021
Resumen:
In this work we propose and demonstrate a Fresnel-lens-inspired method
to focus multiple laser-induced shock waves through time-delay
superposition at arbitrary locations. While the principle works for any
geometry, we demonstrate that this method already achieves focusing with
two pairs of photoacoustic shock wave emitters located on a line centred
around the acoustic axis (z) in a quasi-two-dimensional liquid geometry.
Each emitter pair is created by focusing one laser pulse simultaneously
at two spots with a spatial light modulator at z = 0 mu m with y = +/-
145 mu m and y = +/- 75 mu m. The delays between the emitters necessary
to vary the location of the focus from z approximate to 0 to similar to
206 mu m are 35 and 0 ns, respectively. We find that the location of
constructive superposition is significantly closer to the origin than
what would be expected for linear waves in homogeneous media. This is
confirmed with simulations using an Euler solver that shows the
importance of finite-amplitude effects. The simulated dynamics are in
reasonable agreement with our measurements. Finally, pressure gains at
various locations along the acoustic axis are tested with the response
of gaseous microbubbles acting as pressure probes. The measurements
agree with calculated pressure ratios at different positions.
Filiaciones:
Gutierrez-Hernandez, Ulisses J.:
Univ Nacl Autonoma Mexico, Inst Ciencias Nucl, Apartado Postal 70-543, Mexico City 04510, DF, Mexico
De Colle, Fabio:
Univ Nacl Autonoma Mexico, Inst Ciencias Nucl, Apartado Postal 70-543, Mexico City 04510, DF, Mexico
Ohl, Claus-Dieter:
Otto von Guericke Univ, Inst Phys, Dept Soft Matter, Univ Pl 2, D-39016 Magdeburg, Germany
Quinto-Su, Pedro A.:
Univ Nacl Autonoma Mexico, Inst Ciencias Nucl, Apartado Postal 70-543, Mexico City 04510, DF, Mexico
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