完美涡旋光中微米级粒子的受力与力矩特性分析

基于紧聚焦方法在几何焦平面处获得了完美涡旋光场,理论分析了该光场中微米级尺寸微粒受到的光学力与轨道矩。结果表明,该完美涡旋光可以在横平面上捕获微粒并驱动其绕光轴做轨道旋转运动,微粒受到的轨道矩随着拓扑荷的增大先增大后趋近于稳定。此外,分析了圆偏振、径向偏振和方位角偏振完美涡旋光对微粒施加的光学力和轨道矩。结果表明完美涡旋光的偏振态在一定程度上会影响微粒的轨道运动,圆偏振完美涡旋光更适合用于诱导微粒轨道旋转。

Force and Torque Analysis of Micro-sized Particles in Perfect Optical Vortex Beams

Based on the tightly focusing approach,the perfect optical vortex beams are generated at the geometric focal plane.The optical forces and torques exerted on the micro-sized particle in the perfect optical vortex beams are calculated.Numerical results show that the micro-sized particle is trapped on the ring of perfect optical vortex beams and is driven to rotate around the optical axis.The orbital torque will firstly increases and then tends to be stable with the increase of the topological charge value.In addition,the influence of circular polarization state,radial polarization state and azimuthal polarization state on the force and orbital torque of micro-sized particles are investigated in perfect optical vortex beams.The results show that the state of polarization of perfect optical vortex beams will affect the optically induced orbital motion to some extent.The circular polarization state of perfect optical vortex beams is superior to drive the orbital motion of the particle.