Open AccessNonlinear modulation on optical trapping in a plasmonic bowtie structure
Author(s) -
Wenjun Zhang,
Yuquan Zhang,
Shuoshuo Zhang,
Yulong Wang,
Yang Wu,
Changjun Min,
Xiaocong Yuan
Publication year - 2021
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.422493
Subject(s) - optical tweezers , plasmon , optics , materials science , laser , trapping , modulation (music) , optical force , kerr effect , surface plasmon , excitation , optoelectronics , optical power , nonlinear system , physics , ecology , quantum mechanics , acoustics , biology
Surface plasmon optical tweezers based on micro- and nano-structures are capable of capturing particles in a very small spatial scale and have been widely used in many front research fields. In general, distribution of optical forces and potential wells exerted on the particles can be modulated by controlling the geometric parameters of the structures. However, these fabricated structures are irreversible once processed, which greatly limits its application in dynamic manipulation. The plasmonic field in these structures can be enhanced with orders of magnitude compared to the excitation light, offering a possibility to stimulate nonlinear responses as a new degree of freedom for dynamic modulation. Here, we theoretically demonstrate that the optical force and potential well can be modulated on account of the nonlinear Kerr effect of a gold bowtie structure under a pulsed laser with high peak power. The results verify that the trapping states, including the position, width, and depth of the potential well, can be dynamically modulated by changing intensity of the incident laser. It provides an effective approach for stable trapping and dynamic controlling of particles on nanostructure-based plasmonic trapping platforms and thus has great application potential in many fields, such as enhanced Raman detection, super-resolution imaging, and optical sensing.