  The radiation forces on a Rayleigh dielectric sphere induced by a partially
coherent light beam are greatly affected by the coherence of the light beam.
The magnitude of the radiation forces on a dielectric sphere near the focus
point greatly decreases as the coherence decreases. For the light beam with
good coherence, the radiation force may be used to trap a particle; and for the
light beam with intermediate coherence, the radiation force may be used to
guide and accelerate a particle.
