拉盖尔-高斯光束是典型的涡旋光束,光束的轨道角动量会传递给微粒使其产生轨道运动。本文利用T矩阵方法和麦克斯韦应力张量积分计算了强聚焦线偏振拉盖尔-高斯光束对球形粒子的捕获力,并着重分析了粒子半径和光束阶数对微粒在涡旋聚焦场中运动状态的影响。当光束阶数一定时,随着微粒半径的增大,轨道运动的轨迹会逐渐缩小。当粒子半径大于临界值时,就会被捕获到光轴上,且无法进行轨道运动。但是,离轴捕获的粒子受到的轴向捕获力比轴上捕获的要小一个量级,需要施加足够的入射光功率以维持稳定的轨道运动。
Abstract
Laguerre-Gaussian beams are typical vortex beams,the orbital angular momentum of the beam can be transmitted to the microsphere and make it do an orbital motion.The trapping forces exerted by the highly focused linearly polarized Laguerre-Gaussian beam (LGB) on a spherical particle are calculated by means of the T-matrix method and Maxwell stress tensor integral.The impact of microsphere radius and beam order on the particle′s trapping states in the vortex focusing field are investigated.When the topological charge keeps constant,with the microsphere′s radius increases,the trajectory of the orbital motion will gradually shrink.As its radius is larger than the critical value,the microsphere will be trapped on the optical axis without orbital motion.However,axial trapping forces of particles trapped off-axis are smaller an order of magnitude than those of particles trapped on axis,so that more input optical power is needed to maintain the stable orbital motion.
关键词
拉盖尔-高斯光束 /
涡旋光束 /
T矩阵方法 /
光学捕获 /
轨道运动
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Key words
Laguerre-Gaussian beam /
vortex beam /
T-matrix method /
optical trapping /
orbital motion
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参考文献
[1] Ashkin A.Acceleration and Trapping of Particles by Radiation Pressure[J].Phys Rev Lett,1970,24(4):156-159.
[2] Būtaitё U G,Gibson G M,Ho Y L D,et al.Indirect optical trapping using light driven micro-rotors for reconfigurable hydrodynamic manipulation[J].Nat Commun,2019,10(1):1215.
[3] O′Neil A T,Macvicar I,Allen L,et al.Intrinsic and extrinsic nature of the orbital angular momentum of a light beam[J].Phy Rev Lett,88(5),053601 (2002).
[4] Cao Y,Zhu T,Lv H,et al.Spin-controlled orbital motion in tightly focused high-order Laguerre-Gaussian beams[J].Opt Express,2016,24(4):3377.
[5] Li M M,Yan S H,Yao B L,et al.Spinning and orbiting motion of particles in vortex beams with circular or radial polarizations[J].Opt Express,2016,24(18):20604-20612.
[6] Liang Y,Lei M,Yan S,et al.Rotating of low-refractive-index microparticles with a quasi-perfect optical vortex[J].Appl Opt,2018,57(1):79-84.
[7] Lehmuskero A,Li Y,Johansson P,et al.Plasmonic particles set into fast orbital motion by an optical vortex beam[J].Opt Express,2014,22(4):4349-56.
[8] Zhang Z,Pu J,Wang X.Distribution of phase and orbital angular momentum of tightly focused vortex beams[J].Opt Eng,2008,47(6):587-601.
[9] Irawati N,John V,Aeinehvand M M,et al.Evanescent wave optical trapping and transport of polystyrene microspheres on microfibers[J].Micro Opt Techn Let,2015,56(11):2630-2634.
[10] Chen Z,Pu J,Zhao D.Tight focusing properties of linearly polarized Gaussian beam with a pair of vortices[J].Phys Lett A,2011,375(32):2958-2963.
[11] Chen M,Huang S,Shao W,et al.Optical force and torque on a dielectric Rayleigh particles by a circular Airy vortex beam[J].J Quant Spectrosc R A,2018,208:101-107.
[12] Fan C J,Liu Y X,Wang X Y,et al.Trapping two types of particles by using a tightly focused radially polarized power-exponent-phase vortex beam[J].J Opt Soc Am A,2018,35(6):903-907.
[13] Gu B,Xu D,Rui G,et al.Manipulation of dielectric Rayleigh particles using highly focused elliptically polarized vector fields[J].Appl Opt,2015,54(27):8123-8129.
[14] Li M M,Yan S H,Yao B L,et al.Optically induced rotation of Rayleigh particles by vortex beams with different states of polarization[J].Phys Lett A,2016,1-2(380):311-315.
[15] Otsu T,Ando T,Takiguchi Y,et al.Direct evidence for three-dimensional off-axis trapping with single Laguerre-Gaussian beam[J].Sci Rep,2014,4(13):4579.
[16] Gahagan K T,Swartzlander G A.Optical vortex trapping of particles[J].Opt Lett,1996,21(11):827-829.
[17] Richards B,Wolf E.Electromagnetic Diffraction in Optical Systems.II.Structure of the Image Field in an Aplanatic System[J].Pro R Soc of London.Ser A,1959,253(1274):358-379.
[18] Wu F P,Zhang B,Liu Z L,et al.Optical trapping forces of a focused azimuthally polarized Bessel-Gaussian beam on a double-layered sphere[J].Opt Commu,2017,405:96-100.
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脚注
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基金
中央高校基本科研业务费专项资金(批准号:WUT:2018-IB-010)
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