Lateral optical force on paired isotropic spherical particles in a linearly polarized plane wave

To generate lateral optical force (LOF) on a mirror-symmetric object is still challenging. Here, we demonstrate numerically and analytically that an extraordinary LOF can be induced on paired isotropic spherical particles under the illumination of an obliquely incident linearly polarized (LP) plane wave. Theoretical analysis reveals that the LOF arises from lateral asymmetric scattering between two particles induced by the linear polarization of obliquely incident LP light. The magnitude and sign of the LOF are tunable and reversible by changing the particle separation, incident angle and polarization angle of the incident light. Especially, the LOF shows a sinusoidal dependence on the polarization angle, which enriches the degree of freedom of optical manipulation. The proposed mechanism does not depend on complex structured light or interface and is expected to have practical applications in separating and sorting different dimers.