We report on the experimental demonstration of phase-dependent electromagne
tically induced transparency (EIT). This effect is based on a quantum inter
ference in closed-loop schemes of interaction of atoms with the radiation.
It allows us to control optical properties of the medium by the phases of t
he laser fields. We discuss some of the possible applications of phase-depe
ndent EIT. [S1050-2947(99)01003-3].