Open AccessFDTD numerical simulation of the trapping force of microspherein single optical tweezers
Author(s) -
Hu Geng-Jun,
Jing Li,
Long Qian,
Tao Tao,
Gongxuan Zhang,
Xiaoping Wu
Publication year - 2011
Publication title -
wuli xuebao
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.199
H-Index - 47
ISSN - 1000-3290
DOI - 10.7498/aps.60.030301
Subject(s) - optical tweezers , trapping , optical force , finite difference time domain method , optics , radiation pressure , tweezers , pressure gradient force , polarization (electrochemistry) , gaussian beam , physics , beam (structure) , materials science , radial polarization , laser beam quality , laser , laser beams , chemistry , ecology , biology
In this paper the model of trapping force on microsphere near focus in single optical tweezers is built by three dimensional finite-difference time-domain (FDTD) and Maxwell stress tensor methods. Fifth order Gaussian beam based on spherical vector wave function (VSWF) is adopted as simulation light source; the correct light field transmission is obtained. The influences of the wavelength, waist and polarization of light sources, the radius and refractive index of the microsphere on the optical trapping force are discussed. The influence of nearby microsphere and beam polarization on the trapping force of the trapped microsphere in single optical tweezers is analyzed. The effect of beam polarization working on the trapping force of the trapped microsphere is specially analyzed. As results of simulation, the trapping force acting on the microsphere by the circularly polarized beam is larger than that by the linearly polarized beam. The stability of the trapped microsphere in single optical tweezers will be disturbed by the nearby microsphere and lose its balance. Varying the beam polarization will lead to the change of the trapping force of the trapped microsphere.