Open AccessOpto-thermal oscillation and trapping of light absorbing particles
Author(s) -
Min Zhong,
Ai-Yin Liu,
Feng Ji
Publication year - 2019
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.27.029730
Subject(s) - optical force , trapping , drag , oscillation (cell signaling) , optical tweezers , optics , materials science , temperature gradient , thermal , pressure gradient force , substrate (aquarium) , physics , mechanics , chemistry , ecology , biochemistry , quantum mechanics , meteorology , biology , oceanography , geology
We present an experimental study on opto-thermal oscillation and trapping of light absorbing particles. The oscillation is a three-dimensional motion in the solution. The particles at the lower substrate of the sample cell are driven towards the center of optical trap by the optical force. When the particles arrive at the location near the trap center, the laser heating on the particles results in a strong thermal gradient force that repels the particles to leave the focus spot. Next, the particles slow down under the viscous drag force. At last, the particles settle to the lower substrate of sample cell due to gravity, and restart the new oscillation process. For opto-thermal trapping of the absorbing particles, the particles are dispersed in a thin cell to compress the convention and enhance the viscous resistance. The particles can be trapped close to the spot due to the balance of optical and thermal gradient forces.