title: Laser pulse duration is critical for the generation of plasmonic nanobubbles.
abstract: Plasmonic nanobubbles (PNBs) are transient vapor nanobubbles generated in liquid around laser-overheated plasmonic nanoparticles. Unlike plasmonic nanoparticles, PNBs' properties are still largely unknown due to their highly nonstationary nature. Here we show the influence of the duration of the optical excitation on the energy efficacy and threshold of PNB generation. The combination of picosecond pulsed excitation with the nanoparticle clustering provides the highest energy efficacy and the lowest threshold fluence, around 5 mJ cm(-2), of PNB generation. In contrast, long excitation pulses reduce the energy efficacy of PNB generation by several orders of magnitude. Ultimately, the continuous excitation has the minimal energy efficacy, nine orders of magnitude lower than that for the picosecond excitation. Thus, the duration of the optical excitation of plasmonic nanoparticles can have a stronger effect on the PNB generation than the excitation wavelength, nanoparticle size, shape, or other "stationary" properties of plasmonic nanoparticles.
authors.affiliation: Departments of Biochemistry and Cell Biology and §Department of Physics and Astronomy, Rice University , 6100 Main Street, MS-140, Houston, Texas 77005, United States.
authors.forename: Ekaterina Y
authors.initials: EY
authors.lastname: Lukianova-Hleb
authors.forename: Alexey N
authors.initials: AN
authors.lastname: Volkov
authors.forename: Dmitri O
authors.initials: DO
authors.lastname: Lapotko
mesh_terms: D007834:Lasers; D053768:Metal Nanoparticles / Q000737:chemistry*