20 Décembre – Thesis defense - Benjamin Sanchez Padilla
14 h Amphi A9 (campus de Talence)
Rotational mechanical effects driven by orbital angular momentum transfer of sound waves.
We study the rotational mechanical effects resulting from sound-matter interaction in the presence of orbital angular momentum transfer. A set of experimental realizations are implemented by using ultrasonic waves propagating in the air and 3D printed centimeter-sized objects acting as structured mirrors imparting a helical phase profile to the reflected wave. The main result consists of the quantitative direct measurement of the orbital angular momentum carried by acoustic vortex beams via two independent approaches. The first one is based on the use of a freely rotating helical mirror placed at air-water interface, and the second one relies on the development of a torsional mechanical oscillator driven by acoustic orbital angular momentum.