Acta Photonica Sinica, Volume. 40, Issue 5, 798(2011)
Focusing Characteristics of Laguerre-Gaussian Radially Polarized Beam Through High Numerical Aperture
For the focusing of the optical system with high numerical aperture, the light intensity distribution in the focal region will shows some special characteristics, which can be used in many fields, such as microscopy, particles trapping, data storage etc. Based on the vectorial Deby theory, the focal light intensity distributions of TM01 mode Laguerre-Gaussian radially polarized beam through the optical system with high numerical aperture were studied. By adjusting the ratio of the pupil radius versus beam waist, the focal light spot changed from small bright spot into dark ring spot. Moreover, by the pupil filter, the light intensity distribution in the focal region and the focal dark spot size could be modulated, which could make the intensity of dark area change from 0 to 1. And, by choosing the parameters of pupil filter purposefully, several 3D optical cages could be produced in the focal region, which made particle trapping more efficiently. Moreover, several particles can be trapped at one time, which has great practical value in trapping particles with refractive indices lower than that of surrounding medium.
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WENG Xiao-yu, GUO Han-ming, DONG Xiang-mei, SUI Guo-rong, GAO Xiu-min, ZHUANG Song-lin. Focusing Characteristics of Laguerre-Gaussian Radially Polarized Beam Through High Numerical Aperture[J]. Acta Photonica Sinica, 2011, 40(5): 798
Received: Nov. 25, 2010
Accepted: --
Published Online: Jun. 14, 2011
The Author Email: Xiao-yu WENG (wxy100100@126.com)