Storing light in active optical waveguides with single-negative materials

Abstract

We show that a nonresonant planar waveguide consisting of conventional dielectric cladded with single-negative materials supports degenerate propagating modes for which the group velocity and total energy flow can be zero if the media are lossless. Absorptive losses will destroy the zero-group velocity condition for real frequency/complex wave vector modes. We show that by incorporating gain G into the core dielectric, there exists a critical gain value G/subc/ at which we can recover the condition of zero group velocity, so that light pulses can be stopped and stored. This structure is simpler to achieve than double-negative metamaterials, has small footprint, and can be incorporated into ultracompact on-chip optoelectronics.