Comparison of the orbital and spin rotation of a dielectric particle

We demonstrate a scheme based on a biaxial crystal for generation of the orbital and spin flows in optical fields. Such fields offer a possibility for microparticles’ rotation. By using the spin flow of beams with a gradient trap, refractive dielectric particles can be rotated. We achieved the orbital rotation of such particle due to the combination of an optical vortex trap and a gradient trap in orthogonal linearly polarized incoherent beams. We quantitatively compared the action of the spin and orbital momenta on the same particle of gamboge for its rotational speed.