Evanescent electromagnetic fields near a waveguide can exert a transverse radiation force on scattering objects. To prove this experimentally, we demonstrate light-induced orbiting of isotropic, dielectric microparticles around an optical nanofiber that guides elliptically polarized, fundamental modes. The orbit frequency is proportional to the helicity of the coupled light. Interestingly, the observed motion is opposite to the energy flow circulation around the fiber. This result verifies the theoretically predicted negative optical torque on a sufficiently large particle in the vicinity of a nanofiber.

中文翻译：

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光诱导介电微粒围绕光学纳米纤维的旋转

波导附近的渐逝电磁场可以在散射物体上施加横向辐射力。为了通过实验证明这一点，我们展示了光诱导的各向同性的介电微粒围绕光学纳米纤维的运动，该光学纳米纤维引导着椭圆偏振的基本模式。轨道频率与耦合光的螺旋度成正比。有趣的是，观察到的运动与纤维周围的能量流循环相反。该结果验证了在纳米纤维附近足够大的颗粒上的理论预测的负光学扭矩。