  Spin-to-orbit conversion of light is a dynamical optical phenomenon in
non-paraxial fields leading to various manifestations of the spin and orbital
Hall effect. However, effects of spin-orbit interaction (SOI) have not been
explored extensively for higher order Gaussian beams carrying no intrinsic
orbital angular momentum. Indeed, the SOI effects on such structured beams can
be directly visualized due to azimuthal rotation of their transverse intensity
profiles - a phenomenon we call the rotational Hall effect. In this paper, we
show that for an input circularly polarized (right/left) $HG_{10}$ mode, SOI
leads to a significant azimuthal rotation of the transverse intensity
distribution of both the orthogonal circularly polarized (left/right)
component, and the transverse component of the longitudinal field intensity
with respect to the input intensity profile. We validate our theoretical and
numerically simulated results experimentally by tightly focusing a circularly
polarized $HG_{10}$ beam in an optical tweezers configuration, and projecting
out the opposite circular polarization component and the transverse component
of the longitudinal field intensity at the output of the tweezers. We also
measure the rotational shift as a function of the refractive index contrast in
the path of the tightly focused light, and in general observe a proportional
increase. The enhanced spin-orbit conversion in these cases may lead to
interesting applications in inducing complex dynamics in optically trapped
birefringent particles using higher order Gaussian beams with no intrinsic
orbital angular momentum.
