Trapping Rayleigh particles using highly focused higher-order radially polarized beams |
| |
Authors: | Youyi Zhuang Biaofeng Ding |
| |
Affiliation: | a College of Physics and Electronic Information, Wenzhou University, Wenzhou 325035, Chinab Graduate School of Science and Technology, Kumamoto University, Kumamoto 860-8555, Japan |
| |
Abstract: | The optical trapping characteristics of highly focused higher-order radially polarized beams (R-TEMp1*) acting on a Rayleigh particle are studied theoretically. Numerical results show that as the order p of beam increases and the numerical aperture NAo of the objective decreases, the axial trap distance increases but the trap depth and maximum restoring force decreases. In a limit of NAo = 1, three higher-order R-TEMp1* beams of p = 1, 2, 3, like the fundamental lowest-order radially polarized beam of p = 0, can three-dimensionally trap a particle to the focus but the axial trap stiffness decreases with the increase of p. When NAo = 0.95, the focus is still a stable trap point for the two beams of p = 0 and 1 but it becomes an unstable trap point for the two beams of p = 2 and 3. The trap stability is also discussed for higher-order radially polarized beam illumination. |
| |
Keywords: | Optical trap Higher-order radially polarized beams Vector diffraction Dipole approximation |
本文献已被 ScienceDirect 等数据库收录! |
|