  Electromagnetically induced transparency (EIT) in metastable helium at room
temperature is experimentally shown to exhibit light storage capabilities for
intermediate values of the detuning between the coupling and probe beams and
the center of the atomic Doppler profiles. An additional phase shift is shown
to be imposed to the retrieved pulse of light when the EIT protocol is
performed at non-zero optical detunings. The value of this phase shift is
measured for different optical detunings between 0 and 2 GHz, and its origin is
discussed.
