  We consider the optical dipole potential energy, which arises from the
interaction of a two-level atom with a circularly polarized Laguerre-Gaussian
laser beam of small waist. The beam is characterized by the existence of a
longitudinal electric field component which is responsible for the appearance
of a chiral term in the optical dipole potential energy. This term reverses
sign if either the winding number or the wave polarization of the beam reverses
sign. We propose a scheme of a bi-chromatic vortex interaction with the
two-level atom in which the resulting optical dipole potential is fully chiral.
