应用部分相干理论推导了部分相干贝塞尔涡旋光束经过透镜聚焦后的光强分布表达式。在雷利散射范围内,利用光作用在介质球上的梯度力和散射力公式,主要讨论了拓扑荷数、相干长度、参数α以及介质球的大小选择对于梯度力和散射力的影响。数值模拟结果表明,作用在介质球上的梯度力和散射力随着拓扑荷数、相干长度或参数α的增大而减小。当拓扑荷数为0,1时,稳定的3维光阱能被获得,并且能被应用于操控折射率低于周围媒介的粒子。

The radiation forces of focused partially coherent Bessel vortex beams on a dielectric sphere in the Rayleigh scattering regime are theoretically investigated. Numerical results demonstrate that the magnitude of the radiation forces on a dielectric sphere near the focus point decreases as the topological charge,the coherence length or the parameter α increases. When the topological charge n=0,1,the stable three-dimensional trap can be obtained,and can be used to manipulate the particle with a refractive index lower than that of the ambient media.