强激光与粒子束, 2009, 21 (1): 39, 网络出版: 2009-11-24
相位板偏振偏转角对径向偏振光的梯度力分布的影响
Effect of concentric zones phase plate on gradient force pattern of radially polarized beam
摘要
研究了同心分区偏振偏转相位板对径向偏振光梯度力的调制效应。给出了相位板各部分偏振偏转角不同时,光学梯度力的分布情况。模拟结果表明:随着同心分区相位板各部分的半径和偏振旋转角的改变,光学梯度力方向及大小明显变化,且会产生许多可控的梯度力分布模式,可应用于微粒的收集、分离和合并。结果显示同心分区相位板对径向偏振光的调制可以用来生成可调光镊。
Abstract
The optical gradient force patterns in focal region of radially polarized beams is investigated. The pure phase plate consists of three concentric zones: center circle zone,inner annular zone and outer annular zone. And the phase variance of annular zone is adjustable. The tunable phase plate can be implemented through liquid crystal spatial light modulator,which can conveniently alter the phase shift and polarization rotation angle of each section of the incident laser beam in the control of computer. Numerical simulations show that the evolution of the focal shape is evident by changing polarization rotation angle of each section portion of the vector beam. Consequently,the optical gradient force patterns will change and some interesting optical trap patterns may occur,which shows that radially polarized beams can be used to construct controllable optical tweezers.
李劲松, 高秀敏. 相位板偏振偏转角对径向偏振光的梯度力分布的影响[J]. 强激光与粒子束, 2009, 21(1): 39. Li Jinsong, Gao Xiumin. Effect of concentric zones phase plate on gradient force pattern of radially polarized beam[J]. High Power Laser and Particle Beams, 2009, 21(1): 39.