Optical trapping using transverse electromagnetic (TEM)-like mode in a coaxial nanowaveguide

Yuanhao Lou; Xiongjie Ning; Bei Wu; Yuanjie Pang

doi:10.1007/s12200-021-1134-3

Optical trapping using transverse electromagnetic (TEM)-like mode in a coaxial nanowaveguide

Front Optoelectron. 2021 Dec;14(4):399-406. doi: 10.1007/s12200-021-1134-3. Epub 2021 Apr 7.

Authors

Yuanhao Lou¹, Xiongjie Ning¹, Bei Wu¹, Yuanjie Pang²

Affiliations

¹ School of Optical and Electronic Information, Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan, 430074, China.
² School of Optical and Electronic Information, Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan, 430074, China. yuanjie_pang@hust.edu.cn.

Abstract

Optical traps have emerged as powerful tools for immobilizing and manipulating small particles in three dimensions. Fiber-based optical traps (FOTs) significantly simplify optical setup by creating trapping centers with single or multiple pieces of optical fibers. In addition, they inherit the flexibility and robustness of fiber-optic systems. However, trapping 10-nm-diameter nanoparticles (NPs) using FOTs remains challenging. In this study, we model a coaxial waveguide that works in the optical regime and supports a transverse electromagnetic (TEM)-like mode for NP trapping. Single NPs at waveguide front-end break the symmetry of TEM-like guided mode and lead to high transmission efficiency at far-field, thereby strongly altering light momentum and inducing a large-scale back-action on the particle. We demonstrate, via finite-difference time-domain (FDTD) simulations, that this FOT allows for trapping single 10-nm-diameter NPs at low power.

Keywords: fiber-based optical trap (FOT); metal nanophotonic structures; optical apertures; optical waveguides; plasmonic optical trapping; self-induced back-action.