154 research outputs found
Pure superposition states of atoms generated by a bichromatic elliptically polarized filed
We find specific polarizations of components of a bichromatic field, which
allow one to prepare pure superposition states of atoms, using the coherent
population trapping effect. These states are prepared in the system
of Zeeman substates of the ground-state hyperfine levels with arbitrary angular
momenta and . It is established that, in general case , the
use of waves with elliptical polarizations (
field configuration for alkali metal atoms) is necessary for the pure state
preparation. We analytically show an unique advantage of the D1 line of alkali
metal atoms, which consists in the possibility to generate pure
states even in the absence of spectral resolution of the excited-state
hyperfine levels, contrary to the D2 line.Comment: revtex4, 6 pages including 2 eps figure
Cancellation of light-shifts in an N-resonance clock
We demonstrate that first-order light-shifts can be cancelled for an
all-optical, three-photon-absorption resonance ("N-resonance") on the D1
transition of Rb87. This light-shift cancellation enables improved frequency
stability for an N-resonance clock. For example, using a table-top apparatus
designed for N-resonance spectroscopy, we measured a short-term fractional
frequency stability (Allan deviation) 1.5e-11 tau^(-1/2) for observation times
1s< tau < 50s. Further improvements in frequency stability should be possible
with an apparatus designed as a dedicated N-resonance clock.Comment: 4 pages, 4 figure
Geoecological problems of urban land pollution in contact zones with iron ore production
The article is concerned with the issues of study heavy metal migration in the soils in close proximity to iron ore mining and processing facilities in the territory of Starooskol-Gubkin industrial are
A novel absorption resonance for all-optical atomic clocks
We report an experimental study of an all-optical three-photon-absorption
resonance (known as a "N-resonance") and discuss its potential application as
an alternative to atomic clocks based on coherent population trapping (CPT). We
present measurements of the N-resonance contrast, width and light-shift for the
D1 line of 87Rb with varying buffer gases, and find good agreement with an
analytical model of this novel resonance. The results suggest that N-resonances
are promising for atomic clock applications.Comment: 4 pages, 6 figure
Comparison of 87Rb N-resonances for D1 and D2 transitions
We report an experimental comparison of three-photon-absorption resonances
(known as "N-resonances") for the D_1 and D_2 optical transitions of thermal
87Rb vapor. We find that the D_2 N-resonance has better contrast, a broader
linewidth, and a more symmetric lineshape than the D_1 N-resonance. Taken
together, these factors imply superior performance for frequency standards
operating on alkali D_2 N-resonances, in contrast to coherent population
trapping (CPT) resonances for which the D_2 transition provides poorer
frequency standard performance than the D_1 transition.Comment: 3 pages, 4 figure
Coherent population trapping resonances with linearly polarized light for all-optical miniature atomic clocks
We present a joint theoretical and experimental characterization of the
coherent population trapping (CPT) resonance excited on the D1 line of 87Rb
atoms by bichromatic linearly polarized laser light. We observe high-contrast
transmission resonances (up to 25%), which makes this excitation scheme
promising for miniature all-optical atomic clock applications. We also
demonstrate cancellation of the first-order light shift by proper choice of the
frequencies and relative intensities of the two laser field components. Our
theoretical predictions are in good agreement with the experimental results.Comment: 8 pages, 7 figure
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