论文标题
拉格雷 - 高斯光束悬浮的粒子的异常运动
Anomalous Motion of Particle Levitated by Laguerre-Gaussian beam
论文作者
论文摘要
Laguerre-Gaussian（LG）梁具有轨道角动量（OAM）。由于OAM的转移，被困在LG梁中的粒子将围绕梁轴旋转。粒子的旋转通常与梁绿色的方向相同。但是，我们发现，当LG梁强烈聚焦时，粒子和梁绿色的旋转可能朝相反的方向。这种异常效应是由聚焦LG梁施加的粒子上的负扭矩引起的，该粒子与线性情况下的光拉力相似。我们计算了被浓缩的LG梁形成的光学镊子中的微颗粒的散射力分布，并表明存在由负扭矩控制的粒子的稳定轨迹。我们提出了几个必要条件，以观察违反直觉轨迹。我们的工作表明，被捕获的微粒表现出多种运动模式。
Laguerre-Gaussian (LG) beam has orbital angular momentum (OAM). A particle trapped in an LG beam will rotate about the beam axis, due to the transfer of OAM. The rotation of the particle is usually in the same direction as that of the beam OAM. However, we discovere that when the LG beam is strongly focused, the rotation of the particle and the beam OAM might be in the opposite direction. This anomalous effect is caused by the negative torque on the particle exerted by the focused LG beam, which is similar to the optical pulling force in the linear case. We calculated the scattering force distribution of a micro-particle trapped in an optical tweezers formed by the strongly focused LG beam, and showed that there exist stable trajectories of the particle that controlled by the negative torque. We proposed several necessary conditions for observing the counter-intuitive trajectories. Our work reveals that the strongly trapped micro-particle exhibits diversity of motion patterns.
