Rotating of low-refractive-index microparticles with a quasi-perfect optical vortex


Yansheng Liang and Ming Lei and Shaohui Yan and Manman Li and Yanan Cai and Zhaojun Wang and Xianghua Yu and Baoli Yao


“Low-refractive-index microparticles, such as hollow microspheres, have shown great significance in some applications, such as biomedical sensing and targeted drug delivery. However, optical trapping and manipulation of low-refractive-index microparticles are challenging, owing to the repelling force exerted by typical optical traps. In this paper, we demonstrated optical trapping and rotating of large-sized low-refractive-index microparticles by using quasi-perfect optical vortex (quasi-POV) beams, which were generated by Fourier transform of high-order quasi-Bessel beams. Numerical simulation was carried out to characterize the focusing property of the quasi-POV beams. The dynamics of low-refractive-index microparticles in the quasi-POV with various topological charges was investigated in detail. To improve the trapping and rotating performances of the vortex, a point trap was introduced at the center of the ring. Experimental results showed that the quasi-POV was preferable for manipulation of large-sized low-refractive-index microparticles, with its control of the particles’ rotating velocity dependent only on the topological charge due to the unchanged orbital radius.”

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Publication: Applied Optics
Issue/Year: Applied Optics Volume 57, Issue 1 pp. 79-84
DOI: 10.1364/ao.57.000079