618 research outputs found
Beam splitting and Hong-Ou-Mandel interference for stored light
Storing and release of a quantum light pulse in a medium of atoms in the
tripod configuration are studied. Two complementary sets of control fields are
defined, which lead to independent and complete photon release at two stages.
The system constitutes a new kind of a flexible beam splitter in which the
input and output ports concern photons of the same direction but well separated
in time. A new version of Hong-Ou-Mandel interference is discussed.Comment: 8 pages, 3 figure
Electromagnetically-induced transparency and light storing of a pair of pulses
Electromagnetically-induced transparency and light storing are studied in the
case of a medium of atoms in a double Lambda configuration, both in terms of
dark- and bright-state polatitons and atomic susceptibility. It is proven that
the medium can be made transparent simultaneously for two pulses following
their self-adjusting so that a condition for an adiabatic evolution has become
fulfilled. Analytic formulas are given for the shapes and phases of the
transmitted/stored pulses. The level of transparency can be regulated by
adjusting the heights and phases of the control fields.Comment: text +6 figure
High-precision interferometric measurement of slow and fast temperature changes in static fluid and convective flow
We explore the strengths and limitations of using a standard Michelson
interferometer to sample line-of-sight-averaged temperature in water via two
experimental setups: slow-varying temperature in static fluid and fast
temperature variations in convective flow. The high precision of our
measurements (a few mK) is enabled by the fast response time and high
sensitivity of the interferometer to minute changes in the refractive index of
water caused by temperature variations. These features allow us to detect the
signature of fine fluid dynamical patterns in convective flow in a fully
non-intrusive manner. For example, we are able to observe an asymmetry in the
rising thermal plume (i.e. an asynchronous arrival of two counter-rotating
vortices at the measurement location), which is not possible to resolve with
more traditional (and invasive) techniques, such as RTD (Resistance Temperature
Detector) sensors. These findings, and the overall reliability of our method,
are further corroborated by means of Particle Image Velocimetry and Large Eddy
Simulations. While this method presents inherent limitations (mainly stemming
from the line-of-sight-averaged nature of its results), its non-intrusiveness
and robustness, along with the ability to readily yield real-time, highly
accurate measurements, render this technique very attractive for a wide range
of applications in experimental fluid dynamics
Coherent processing of a light pulse stored in a medium of four-level atoms
It is demonstrated that the properties of light stored in a four-level atomic
system can be modified by an additional control interaction present during the
storage stage. By choosing the pulse area of this interaction one can in
particular continuously switch between two channels into which light is
released.Comment: text+4 figure
Light slowdown in the vicinity of cross-over resonances
Pulse propagation is considered in an inhomogeneously broadened medium of
three-level atoms in a V-configuration, dressed by a counter-propagating pump
pulse. A significant signal slowdown is demonstrated in this of the three
frequency windows of a reduced absorption and a steep normal dispersion, which
is due to a cross-over resonance. Particular properties of the group index in
the vicinity of such a resonance are demonstrated in the case of closely spaced
upper levels.Comment: 4 figure
Ultra-Narrow Faraday Rotation Filter at the Rb D1 Line
We present a theoretical and experimental study of the ultra-narrow bandwidth
Faraday anomalous dispersion optical filter (FADOF) operating at the rubidium
D1 line (795 nm). This atomic line gives better performance than other lines
for the main FADOF figures of merit, e.g. simultaneously 71% transmission, 445
MHz bandwidth and 1.2 GHz equivalent noise bandwidth.Comment: 3 pages, 2 figures. Manuscript same as v1. FADOF calculator
(ancillary file) now allows for extension to the D2 lin
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