Dynamics of transient microbubbles generated by fs-laser irradiation of plasmonic micropyramids

We investigated the dynamics of microbubbles induced by fs-laser irradiation of plasmonic micropyramids in water. We simulated the localized plasmonic enhancement on the micropyramids using a finite-difference time-domain (FDTD) technique and experimentally confirmed the enhancement by observing the laser-induced damage pattern on the substrate. Finally, we experimentally observed the generation of micrometer-sized bubbles on our fabricated structures. We find that the maximum bubble diameter and bubble lifetime depend on power, exposure time, and repetition rate of the laser. The maximum bubble diameter increases with laser exposure time until a balance is reached between the surface tension and the pressure inside and outside the bubble.