  We report on the observation of spin dependent optically dressed states and
optical Stark effect on an individual Mn spin in a semiconductor quantum dot.
The vacuum-to-exciton or the exciton-to-biexciton transitions in a Mn-doped
quantum dot are optically dressed by a strong laser field and the resulting
spectral signature is measured in photoluminescence. We demonstrate that the
energy of any spin state of a Mn atom can be independently tuned using the
optical Stark effect induced by a control laser. High resolution spectroscopy
reveals a power, polarization and detuning dependent Autler-Townes splitting of
each optical transition of the Mn-doped quantum dot. This experiment
demonstrates a complete optical resonant control of the exciton-Mn system.
