Optical-wave group-velocity reduction without electromagnetically induced transparency

Abstract
A Raman scheme for optical-pulse group-velocity reduction in a pure lifetime broadened system is studied. We show that this nonelectromagnetically induced transparency (NEIT) scheme has many advantages over the conventional method that critically relies on the transparency window created by an EIT process. Significant reduction of the group velocity, probe field loss, and pulse distortion are reported. In addition, rich dynamics of the propagation process are studied.