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Optical Trapping with Focused Surface Waves |
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| Authors: | Yifeng Xiang Xi Tang Changjun Min Guanghao Rui Yan Kuai Fengya Lu Pei Wang Hai Ming Qiwen Zhan Xiaocong Yuan Joseph R Lakowicz Douguo Zhang |
| Institution: | 1. Department of Optics and Optical Engineering, Institute of Photonics, University of Science and Technology of China, Hefei, Anhui, 230026 China;2. Nanophotonics Research Centre, Shenzhen Key Laboratory of Micro-Scale Optical Information Technology, Shenzhen University, Shenzhen, Guangdong, 518060 China;3. Advanced Photonics Center, Southeast University, Nanjing, Jiangsu, 210096 China;4. Department of Electro-Optics and Photonics, University of Dayton, 300 College Park, Dayton, OH, 45469-2951 USA
School of Optical-Electrical and Computer Engineering, University of Shanghai for Science and Technology, Shanghai, 200093 China;5. Center for Fluorescence Spectroscopy, Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, 725 West Lombard St., Baltimore, MD, 21201 USA |
| Abstract: | Near-field optical trapping can be realized with focused evanescent waves that are excited at the water–glass interface due to the total internal reflection, or with focused plasmonic waves excited on the water–gold interface. Herein, the performance of these two kinds of near-field optical trapping techniques is compared using the same optical microscope configuration. Experimental results show that only a single-micron polystyrene bead can be trapped by the focused evanescent waves, whereas many beads are simultaneously attracted to the center of the excited region by focused plasmonic waves. This difference in trapping behavior is analyzed from the electric field intensity distributions of these two kinds of focused surface waves and the difference in trapping behavior is attributed to photothermal effects due to the light absorption by the gold film. |
| Keywords: | evanescent waves optical trapping optothermal effects surface plasmons thermal convection |