Light distribution analysis of optical fibre probe-based near-field optical tweezers using FDTD
Optical fibre probe-based near-field optical tweezers overcomes the diffraction limit of conventional optical tweezers, utilizing strong mechanical forces and torque associated with highly enhanced electric fields to trap and manipulate nanoscale particles. Near-field evanescent wave generated at optical fibre probe decays rapidly with the distance that results a significant reduced trapping volume, thus it is necessary to analyze the nearfield distribution of optical fibre probe. The finite difference time domain (FDTD) method is applied to characterize the near-field distribution of optical fibre probe. In terms of the distribution patterns, depolarization and polarization, the near-field distributions in longitudinal sections and crosssections of tapered metal-coated optical fibre probe are calculated. The calculation results reveal that the incident polarized wave becomes depolarized after exiting from the nano-scale aperture of probe. The near-field distribution of the probe is unsymmetrical, and the near-field distribution in the cross-section vertical to the incident polarized wave is different from that in the cross-section parallel to the incident polarized wave. Moreover, the polarization of incident wave has a great impact on the light intensity distribution.
B H Liu L J Yang Y Wang
School of Mechanical and Electrical Engineering,Harbin Institute of Technology,Heilongjiang,Harbin,150001,China
国际会议
The 8th China International Nanoscience and Technology Symposium(2009第八届中国国际纳米科技湘潭研讨会Cinsts09)
湖南湘潭
英文
1-6
2009-10-23（万方平台首次上网日期，不代表论文的发表时间）