@article{a73a929e37a84bfdbd60c68bc3705ef5,
title = "Resonantly Enhanced Optical Trapping of Single Dye-Doped Particles at an Interface",
abstract = "The optical resonance between an absorbing particle and the trapping laser can enhance the radiation force exerted on micro/nanoscale objects. However, the exact mechanism behind this resonance is still elusive. To unravel the phenomenon, we studied the resonance between a single dye-doped polystyrene particle and a 1064 nm trapping laser under specifically designed optical conditions. The dye-doped particle was trapped at a water-glass interface while simultaneously being excited by a 488 nm widefield laser. In contrast with former reports ({\^a} 10-35% trapping stiffness enhancement), we obtained an unprecedented 4-fold trapping stiffness enhancement due to resonant excitation. When we photobleached the embedded dyes as a control, the trapping stiffness enhancement was no longer observed. Based on nonlinear resonant radiation force theory and the experimental data obtained with a three-dimensional multiplane microscope, we propose that the widefield laser excites the dye to S1 and the trapping laser induces a simultaneous ultrafast S1-S2-S1 cyclic transition, resonantly enhancing the induced dye polarization and, consequently, the radiation force. The elucidation of the optical resonance effect is expected to ultimately enable single molecule manipulation in solution at room temperature.",
keywords = "nonlinear optics, optical force, optical resonance effect, optical trapping, single particle trapping",
author = "Roger Bresol{\'i}-Obach and Tetsuhiro Kudo and Boris Louis and Chang, {Yu Chia} and Scheblykin, {Ivan G.} and Hiroshi Masuhara and Johan Hofkens",
note = "Funding Information: We thank Prof. Hiroshi Miyasaka, Prof. Shoji Ito, and co-worker from Osaka University for measuring the fluorescence lifetime of our dye sample. This work was supported by the Flemish Government through long-term structural funding Methusalem ((CASAS2, Meth/15/04), by Ministry of Science and Technology (MOST) of Taiwan (MOST 109-2113-M-009-022- to H.M., and MOST 108-2112-M-009-008- to T.K.), by the Fonds voor Wetenschappelijk Ondezzoek-Vlaanderen (FWO) (grant W002221N) and by a bilateral agreement between FWO and MOST (grant VS00721N). R.B.-O. thanks the FWO for a postdoctoral fellowship and a long stay abroad grant (12Z8120N and V413820N, respectively). T.K. is thankful for the support from JSPS KAKENHI Grant Number JP 21K14555. H.M. thanks the Ministry of Science and Technology, Taiwan (Grant No. MOST 109-2634-F-009-028) and the Center for Emergent Functional Matter Science of National Chiao Tung University from The Featured Areas Research Center Program within the framework of the Higher Education Sprout Project by the Ministry of Education (MOE) in Taiwan. I.S. thanks the Swedish Research Council (2016-4433). Publisher Copyright: {\textcopyright} ",
year = "2021",
month = jun,
day = "16",
doi = "10.1021/acsphotonics.1c00438",
language = "English",
volume = "8",
pages = "1832--1839",
journal = "ACS Photonics",
issn = "2330-4022",
publisher = "American Chemical Society",
number = "6",
}