135 research outputs found
The evolution and revival structure of angular momentum quantum wave packets (Tutorial)
In this paper a coherent superposition of angular momentum states created by
absorption of polarized light by molecules is analyzed. Attention is paid to
the time evolution of wave packets representing spatial orientation of
internuclear axis of diatomic molecule. Two examples are considered in detail.
Molecules absorbing light in a permanent magnetic field experiencing Zeeman
effect and molecules absorbing light in a permanent electric field experiencing
quadratic Stark effect. In a magnetic field we have a wave packet that evolves
in time exactly as classical dipole oscillator in a permanent magnetic field.
In the second case we have the wave packet that goes through periodical changes
of a shape of the packet and revivals of initial shape. This is a pure quantum
behavior. Classical motion of angular momentum in an electric field in case of
quadratic Stark effect is known to be aperiodic. Obtained solutions for wave
packet evolution are briefly compared with Rydberg state coherent wave packets
and harmonic oscillator wave packets.Comment: LaTeX, 3 figure
Angular momentum spatial distribution symmetry breaking in Rb by an external magnetic field
Excited state angular momentum alignment -- orientation conversion for atoms
with hyperfine structure in presence of an external magnetic field is
investigated. Transversal orientation in these conditions is reported for the
first time. This phenomenon occurs under Paschen Back conditions at
intermediate magnetic field strength. Weak radiation from a linearly polarized
diode laser is used to excite Rb atoms in a cell. The laser beam is polarized
at an angle of pi/4 with respect to the external magnetic field direction.
Ground state hyperfine levels of the 5S_1/2 state are resolved using
laser-induced fluorescence spectroscopy under conditions for which all excited
5P_3/2 state hyperfine components are excited simultaneously. Circularly
polarized fluorescence is observed to be emitted in the direction perpendicular
to both to the direction of the magnetic field B and direction of the light
polarization E. The obtained circularity is shown to be in quantitative
agreement with theoretical predictions.Comment: Accepted for publication in Phys. Rev.
Cascade coherence transfer and magneto-optical resonances at 455 nm excitation of Cesium
We present and experimental and theoretical study of nonlinear
magneto-optical resonances observed in the fluorescence to the ground state
from the 7P_{3/2} state of cesium, which was populated directly by laser
radiation at 455 nm, and from the 6P_{1/2} and 6P_{3/2} states, which were
populated via cascade transitions that started from the 7P_{3/2} state and
passed through various intermediate states. The laser-induced fluorescence
(LIF) was observed as the magnetic field was scanned through zero. Signals were
recorded for the two orthogonal, linearly polarized components of the LIF. We
compared the measured signals with the results of calculations from a model
that was based on the optical Bloch equations and averaged over the Doppler
profile. This model was adapted from a model that had been developed for D_1
and D_2 excitation of alkali metal atoms. The calculations agree quite well
with the measurements, especially when taking into account the fact that some
experimental parameters were only estimated in the model.Comment: small changes to text of previous version; 12 pages, 8 figure
Dynamic effects in nonlinear magneto-optics of atoms and molecules
A brief review is given of topics relating to dynamical processes arising in
nonlinear interactions between light and resonant systems (atoms or molecules)
in the presence of a magnetic field.Comment: 15 pages, 11 figure
Dichroic atomic vapor laser lock with multi-gigahertz stabilization range
A dichroic atomic vapor laser lock (DAVLL) system exploiting
buffer-gas-filled millimeter-scale vapor cells is presented. This system offers
similar stability as achievable with conventional DAVLL system using bulk vapor
cells, but has several important advantages. In addition to its compactness, it
may provide continuous stabilization in a multi-gigahertz range around the
optical transition. This range may be controlled either by changing the
temperature of the vapor or by application of a buffer gas under an appropriate
pressure. In particular, we experimentally demonstrate the ability of the
system to lock the laser frequency between two hyperfine components of the
Rb ground state or as far as 16 GHz away from the closest optical
transition.Comment: 11 pages, 7 figures. Published in Review of Scientific Instruments
201
Implementation of a double-scanning technique for studies of the Hanle effect in Rubidium vapor
We have studied the resonance fluorescence of a room-temperature rubidium
vapor exited to the atomic 5P3/2 state (D2 line) by powerful single-frequency
cw laser radiation (1.25 W/cm^2) in the presence of a magnetic field. In these
studies, the slow, linear scanning of the laser frequency across the hyperfine
transitions of the D2 line is combined with a fast linear scanning of the
applied magnetic field, which allows us to record frequency-dependent Hanle
resonances from all the groups of hyperfine transitions including V- and Lambda
- type systems. Rate equations were used to simulate fluorescence signals for
85Rb due to circularly polarized exciting laser radiation with different mean
frequency values and laser intensity values. The simulation show a dependance
of the fluorescence on the magnetic field. The Doppler effect was taken into
account by averaging the calculated signals over different velocity groups.
Theoretical calculations give a width of the signal peak in good agreement with
experiment
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