  For several decades, ions have been trapped by radio frequency (RF) and
neutral particles by optical fields. We implement the experimental
proof-of-principle for trapping an ion in an optical dipole trap. While
loading, initialization and final detection are performed in a RF trap, in
between, this RF trap is completely disabled and substituted by the optical
trap. The measured lifetime of milliseconds allows for hundreds of oscillations
within the optical potential. It is mainly limited by heating due to photon
scattering. In future experiments the lifetime may be increased by further
detuning the laser and cooling the ion. We demonstrate the prerequisite to
merge both trapping techniques in hybrid setups to the point of trapping ions
and atoms in the same optical potential.
