P.A. Quinto-Su
C.D. Ohl
School of Physical and Mathematical Sciences
Department of Physics and Applied Physics
Nanyang Technological University
Twenty-five laser-induced cavitation bubbles are created simultaneously inside a thin liquid gap using a single laser pulse.
On this picture the array of bubbles is imaged with time-lapse photography at 6 microseconds after the arrival of the laser pulse, the width of the frame is 188 micrometers. The bubbles are deformed due to strong interactions with neighboring bubbles. In addition, bubble shielding leads to a delayed collapse of the central bubbles that experience mainly vapor pressure. The outer bubbles collapse due to the static pressure of the surrounding liquid.
On this image it can be seen that the bubbles on the periphery are already collapsing, while the bubbles at the center have almost reached their maximum size. To create the array of bubbles the spatial profile of the laser is shaped into 25 foci using a spatial light modulator. In this way, arbitrary arrays of bubbles can be created by changing the digital hologram projected on the spatial light modulator.
This work was funded by NTU Singapore.
Reporters can freely use this image. Credit: Cavitation lab, SPMS Nanyang Technological University