Tunable transverse optical force via nonreciprocity

The transverse optical force adds an extra degree of freedom for optical manipulation. In this paper, based on the full wave simulation, we find that an achiral sphere can experience a transverse optical force in the field of a circularly polarized or linearly diagonally polarized electric dipole source in the vicinity of a doped InSb substrate. When the dipole is circularly polarized, the transverse force results from the asymmetrical distribution of the excited surface waves. However, when the dipole is linearly diagonally polarized, the transverse force stems from the combined effect of the surface waves and asymmetrical propagating waves. More importantly, the magnitude and direction of the transverse force can be adjusted by applying a magnetic field parallel to the InSb substrate, due to the generated additional nonreciprocity. Our paper expands the scope of transverse optical force by nonreciprocity.