  We report on highly effective trapping of cold atoms by a new method for a
stable single optical trap in the near-optical resonant regime. An optical trap
with the near-optical resonance condition consists of not only the dipole but
also the radiative forces, while a trap using a far-off resonance dominates
only the dipole force. We estimate a near-optical resonant trap for ultracold
rubidium atoms in the range between -0.373 and -2.23 THz from the resonance.
The time dependence of the trapped atoms indicates some difference of the
stable center-of-mass positions in the near-optical resonant trap, and also
indicates that the differences are caused by the change of the equilibrium
condition of the optical dipole and radiative forces. A stable position depends
only on laser detuning due to the change in the radiative force; however, the
position is ineffective against the change in the laser intensity, which
results in a change in the radiative force.
