1,864 research outputs found
Electromagnetically induced coherent backscattering
We demonstrate a strong coherent backward wave oscillation using forward
propagating fields only. This is achieved by applying laser fields to an
ultra-dispersive medium with proper chosen detunings to excite a molecular
vibrational coherence that corresponds to a backward propagating wave. The
physics then has much in common with propagation of ultra-slow light.
Applications to coherent scattering and remote sensing are discussed
Group velocity study in hot Rb vapor with buffer gas
We study the behavior of the group velocity of light under conditions of
electromagnetically induced transparency (EIT) in a Doppler broadened medium.
Specifically, we show how the group delay (or group velocity) of probe and
generated Stokes fields depends on the one-photon detuning of drive and probe
fields. We find that for atoms in a buffer gas the group velocity decreases
with positive one-photon detuning of the drive fields, and increases when the
fields are red detuned. This dependence is counter-intuitive to what would be
expected if the one-photon detuning resulted in an interaction of the light
with the resonant velocity subgroup.Comment: 6 pages, 7 figure
Coherent control of atomic excitation using off-resonant strong few-cycle pulses
We study the dynamics of a two-level system driven by an off-resonant
few-cycle pulse which has a phase jump at , in contrast to many
cycle pulses, under non rotating-wave approximation (NRWA). We give a closed
form analytical solution for the evolution of the probability amplitude for the upper level. Using the appropriate pulse parameters like
phase-jump , jump time , pulse width , frequency and
Rabi frequency the population transfer, after the pulse is gone,
can be optimized and for the pulse considered here, enhancement of
factor was obtained.Comment: 5 Pages, 7 Figure
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