摘要
根据矢量衍射理论和部分相干理论,推导了部分相干圆偏振反常涡旋光束经过高数值孔径聚焦透镜后的光强表达式。详细讨论了入射光束参数以及聚焦透镜的数值孔径大小对光束紧聚焦特性的影响。研究结果表明:自旋方向,拓扑荷数以及数值孔径大小对光强分布有影响,相干长度以及光束阶数仅改变光强值,光束经过紧聚焦后在轴向方向上自旋角动量可以转换为轨道角动量。此外,研究了紧聚焦后光束对金属瑞利粒子的辐射力。研究表明:低阶光学参数的部分相干左旋圆偏振反常涡旋光束形成的实心光强分布可对金属瑞利粒子捕获。研究结果对部分相干涡旋光束在光镊中的应用具有理论价值。
Based on the vector diffraction theory and partial coherence theory,analytical expressions of the tightly focused partially coherent circularly polarized anomalous vortex beam are derived.Simulation results show the tight focusing properties are strongly dependent on the optical parameters of incident beam and numerical aperture(NA)value.In particular,the spin direction,NA value and the topological charge can be used to modulate the beam profile,whereas the beam order and coherence length only affect the maximal intensity.The spin angular momentum can be transformed into the orbital angular momentum along the axial component after tight focusing.Besides,for left-handed circular polarization,the optical forces of such beam on metallic Rayleigh particles are studied.The results show such a beam can trap metallic Rayleigh particles,which exhibit potential applications on optical tweezers.
作者
董淼
姚骏
白毅华
DONG Miao;YAO Jun;BAI Yi-hua(School of Physics,University of Electronic Science and Technology of China,Chengdu 610054,China)
出处
《激光与红外》
CAS
CSCD
北大核心
2021年第4期502-508,共7页
Laser & Infrared
关键词
涡旋光束
部分相干光束
紧聚焦
辐射力
vortex beam
partially coherent beam
tight focus
optical forces
