We performed optical pulse propagation experiments in a system in which two ultrahigh-Q
silica microspheres of different diameters were coupled in tandem to a fiber taper to yield …

Atomic media have played a major role in studies of fast light. One of their attractive features
is the ability to manipulate experimental parameters to control the dispersive properties that …

We show how the application of a coupling field connecting the two lower metastable states
of a Λ system can produce a variety of effects on the propagation of a weak electromagnetic …

We were able to arbitrarily control the speed of a light pulse from subluminal to superluminal
velocity by changing only the power of the laser for coupling coherently the single transition …

This paper deals with the apparent superluminal propagation of electromagnetic pulses in a
linear dispersive medium. One specifically examines the possibility that the pulse leaving …

We demonstrate coherent control of single-photon absorption and reemission in a two-level
cold atomic ensemble. This is achieved by interfering the incident single-photon wave …

We report superluminal propagation in optical fibers using Brillouin lasing oscillation in a
ring cavity. Negative group velocity propagation through a 10-m single mode fiber has been …

The light propagation of a probe field pulse in a four-level double-lambda type system driven
by laser fields that form a closed interaction loop is studied. The finite frequency width of the …

Slow and superluminal group velocities can be observed in any material that has large
normal or anomalous dispersion. While this fact has been known for more than a century …

For a three-level electromagnetically induced transparency (EIT) atomic system, we show
that, adding a third driving field coupled to a fourth state, the properties of the weak probe …