Longer axial trap distance and larger radial trap stiffness using a double-ring radially polarized beam.
The optical trapping forces acting on a metallic Rayleigh particle are calculated for the case where a double-ring-shaped radially polarized beam is applied. The influence of the off-focus distance and the off-axis distance of a trapping particle on the trapping force is investigated. Compared with the use of the conventional single-ring-shaped radially polarized beam, the longer axial trap distance and the larger radial trap stiffness are predicted using a double-ring-shaped radially polarized beam in an optical trap. These features are useful for improving the trapping ability of an optical trap system where a longer axial trap distance is needed.
Zhang
Yaoju
Y
College of Physics and Electronic Information, Wenzhou University, Wenzhou 325035, China. zhangyaoju@sohu.com
Suyama
Taikei
T
Ding
Biaofeng
B