16 research outputs found
Enhancement of field generation via maximal atomic coherence prepared by fast adiabatic passage in Rb vapor
We have experimentally demonstrated the enhancement of coherent Raman
scattering in Rb atomic vapor by exciting atomic coherence with fractional
stimulated Raman adiabatic passage. Experimental results are in good agreement
with numerical simulations. The results support the possibility of increasing
the sensitivity of CARS by preparing atomic or molecular coherence using short
pulses
Ultralow-power local laser control of the dimer density in alkali-metal vapors through photodesorption
Ultralow-power diode-laser radiation is employed to induce photodesorption of
cesium from a partially transparent thin-film cesium adsorbate on a solid
surface. Using resonant Raman spectroscopy, we demonstrate that this
photodesorption process enables an accurate local optical control of the
density of dimer molecules in alkali-metal vapors.Comment: 4 pages, 4 figure
Electromagnetically induced transparency controlled by a microwave field
We have experimentally studied propagation of two optical fields in a dense
rubidium (Rb) vapor in the case when an additional microwave field is coupled
to the hyperfine levels of Rb atoms. The Rb energy levels form a close-lambda
three-level system coupled to the optical fields and the microwave field. It
has been found that the maximum transmission of a probe field depends on the
relative phase between the optical and the microwave fields. We have observed
both constructive and destructive interference in electromagnetically induced
transparency (EIT). A simple theoretical model and a numerical simulation have
been developed to explain the observed experimental results.Comment: 7 pages, 6 figure
Electromagnetically induced magnetochiral anisotropy in a resonant medium
Chirality has been extensively studied for well over a century, and its potential applications range from optics to chemistry, medicine, and biology. Ingenious experiments have been designed to measure this naturally small effect. Here we discuss the possibility of producing a medium having a large chiral effect by using the ideas of coherent control. The coherent fields resonant with appropriate transitions in atomic or molecular systems can be used to manipulate the optical properties of a medium. We demonstrate experimentally very large magnetochiral anisotropy by using electromagnetic fields in atomic Rb vapors.Peer reviewedPhysic
Vacuum Squeezing in Atomic Media via Self-Rotation
When linearly polarized light propagates through a medium in which
elliptically polarized light would undergo self-rotation, squeezed vacuum can
appear in the orthogonal polarization. A simple relationship between
self-rotation and the degree of vacuum squeezing is developed. Taking into
account absorption, we find the optimum conditions for squeezing in any medium
that can produce self-rotation. We then find analytic expressions for the
amount of vacuum squeezing produced by an atomic vapor when light is
near-resonant with a transition between various low-angular-momentum states.
Finally, we consider a gas of multi-level Rb atoms, and analyze squeezing for
light tuned near the D-lines under realistic conditions.Comment: 10 pages, 6 figures; Submitted to PR
Resonant nonlinear magneto-optical effects in atoms
In this article, we review the history, current status, physical mechanisms,
experimental methods, and applications of nonlinear magneto-optical effects in
atomic vapors. We begin by describing the pioneering work of Macaluso and
Corbino over a century ago on linear magneto-optical effects (in which the
properties of the medium do not depend on the light power) in the vicinity of
atomic resonances, and contrast these effects with various nonlinear
magneto-optical phenomena that have been studied both theoretically and
experimentally since the late 1960s. In recent years, the field of nonlinear
magneto-optics has experienced a revival of interest that has led to a number
of developments, including the observation of ultra-narrow (1-Hz)
magneto-optical resonances, applications in sensitive magnetometry, nonlinear
magneto-optical tomography, and the possibility of a search for parity- and
time-reversal-invariance violation in atoms.Comment: 51 pages, 23 figures, to appear in Rev. Mod. Phys. in Oct. 2002,
Figure added, typos corrected, text edited for clarit
Femtosecond wave-packet dynamics in cesium dimers studied through controlled stimulated emission
Article on femtosecond wave-packet dynamics in cesium dimers studied through controlled stimulated emission
Matching of a stripe injection laser to an external resonator MIRRORS, RESONATORS Matching of a stripe injection laser to an external resonator
Theoretical and experimental investigations of the characteristics of matching of a planar active waveguide to an external axially symmetric resonator are reported. The dependences of the threshold current on the external resonator length are obtained for stripe injection lasers with the waveguide amplification effect. These dependences are shown to be opposite for a resonator with a parallel beam in the external part and for a system with beam focusing by an external mirror. In the case of lasers with a dispersive external resonator the slopes of the dependences are sensitive to the spectral tuning of a selective element. It is shown that the observed characteristics of the dependences of the threshold pumping rate on the length of the external resonator are related to the change in the curvature of the wavefront of the field during the passage through the external part