  We show that the closed-loop control obtained by feeding back the derivative
of the signal from the homodyne measurement of one mode of the light exiting a
two-mode optical cavity interacting with a mechanical resonator permits to
control and increase optical output entanglement. In particular, the proposed
feedback-enhanced setup allows to achieve a fidelity of coherent state
teleportation greater than the threshold value of 2/3 for secure teleportation,
and two-way steering between the two cavity's output modes down the line in
presence of loss, which otherwise would not be possible without feedback
