Lateral optical forces on linearly polarized emitters near a reciprocal substrate

Hafssaa Latioui and Mário G. Silveirinha

We theoretically investigate the conditions for the emergence of lateral (recoil) optical forces on generic dipole-type emitters positioned nearby a reciprocal translation-invariant substrate. Surprisingly, we find that for linearly polarized electric dipoles and for a gradientless excitation the lateral force invariably vanishes, independent of the anisotropy (e.g., tilted optical axes) or chirality of the substrate. We identify an opportunity to have a recoil force relying on a superposition of two linearly polarized and collinear electric and magnetic dipoles. Counterintuitively, it is shown that when such an emitter stands above a uniaxial dielectric half-space with tilted optical axes it may experience a recoil force oriented along the direction perpendicular to the plane defined by the interface normal and the substrate optical axis.

DOI