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Summary form only given. We have experimentally investigated the potential of narrow coherent population trapping resonances for precision applications like magnetometry or atomic frequency standards. CPT can be observed in /spl Lambda/ systems where two ground states are coupled to a common excited state by two near-resonant light fields. Effective formation of ground state coherences takes place...
Based on the model of the Λ-type three-level atomic system, the principle, the evolutionary equations and the resonance line characteristics of the coherent population trapping (CPT) are analyzed by means of ensemble-averaged density matrix approach. The paper presents a schematic illustration of practical realization and a block scheme of comprehensive analysis of the CPT system. Using vertical-cavity...
The squeezing properties of optical field and atomic laser are studied in the system of two-mode SU (1, 1) coherent states interacting with two-level atomic BEC. The results show that two quadrature components of optical field can be squeezed periodically. The frequency of squeezing of optical field depends closely on both the interaction among atoms in BEC and the coupling constant between optical...
Entanglement evolution of two atoms is related to the field mode structure in an optical resonant cavity when the atoms are moving and the optical field is in coherent state. We know the evolvement of entanglement of two atoms is disorderly when two atoms in the cavity are fixed at initial time. However, the evolvement of entanglement of two atoms becomes well-regulated orderly under the coherent...
A major obstacle for optical clocks is the frequency shift due to blackbody radiation (BBR). We discuss how one can tackle this problem in an optical lattice clock, in our case, 87Sr: first, by a measurement of the dc-Stark shift of the clock transition and, second, by interrogating the atoms in a cryogenic environment. Both approaches rely on transporting ultracold atoms over several centimeters...
The ITM is used to describe the MI of atoms of gases under the bicolor femtosecond laser irradiation. The obtained formulas are applied for the qualitative explanation of recent experiments on the generation of THz radiation from an optical breakdown in a focus spot of a femtosecond laser in a gas.
In a three-level lambda system, a destructive interference between excitation pathways at laser excitation can provide the resonant reduction of fluorescence and absorption (“dark resonance”). The dark resonances in rubidium vapor excited by a femtosecond laser or laser with frequency shifted feedback have been studied theoretically and experimentally.
Multiphoton transitions in the Ba atom are experimentally studied in the presence of strong nonresonant radiation that additionally polarizes atoms in the ground state. It is found that the additionally induced polarization of Ba atoms leads to an increase in the probability of multiphoton transitions from this state.
This paper reports an analytical calculation of the populations of the Zeeman sublevels of the cesium atom. We use a circularly polarized laser beam to pump the Cs-cell in the geomagnetic field. Using the approximate form of the optical Bloch equations, we obtain the time evolution functions of the populations of the Zeeman sublevels S1/2(F=4, mF=-4) and P1/2(F=4, mF=-3). The case of the laser detuning...
By combining the pulse molecular beam technique and time of flight mass spectrum, the multiphoton resonance ionization of Xe in the vicinity of 440 nm is studied. The dependence of resonant ionization on laser energy and source pressure of Xe was analyzed and discussed. The resonant ionization spectrum near 440 nm was obtained and the AC Stark effect was determined to be the major cause of asymmetric...
We report our recent progress made with the NRC 88Sr+ single-ion optical frequency standard. The long-term operation of the standard was improved by actively stabilizing the cooling, repump and clearout laser sources, and by using a femtosecond fiber laser frequency comb to link the probe laser frequency to the microwave time standards. With the femtosecond fiber comb, we have demonstrated continuous...
Spectroscopy of atoms in Rydberg states was an object of extensive investigation (see for example [1-5] and references therein). Usually necessary population of Rydberg states is achieved by means of multi-stage pulse laser pumping. That is why useful signal of ionization current from Single Channel Electron Multiplier (CEM or channeltron) is also pulse signal. Essential temporal instability of this...
We demonstrate the use of a moving optical one-way barrier for cooling a collection of atoms, and how sensitive this method is to varying experimental parameters.
We theoretically propose a strategy to use a travelling monochromatic wave in a simple two level atomic system to tune the group velocity over a wide range. Both subliminal and superluminal group velocity are demonstrated from the interaction of a light wave with atoms in the case where the cell length is much less than the light beam diameter. The tunable control of the light group velocity for the...
We propose a new approach for the design of a cavity for atom vapor based devices, where atomic manipulation via two frequencies is required. The cavity provides a homogenous field at two different frequency bands -6.8 GHz and 2 MHz; the first frequency is supported by a cylindrical resonator with conductive walls and dielectric bases, the second frequency is applied from an external source and penetrates...
Terahertz (THz) emissions of an isolated atom in an ultrashort (100 fs) laser field are simulated by solving the time-dependent Schroumldinger equation. From numerical calculations with one- and three-dimensional hydrogen atom models and a short-range shallow potential model, it can be concluded that continuum THz emissions occur more readily following transitions involving intermediate states above...
The effect of optical pumping on the transmission spectra of rubidium is investigated. We found that maximum transmission increased (decreased and gradually increased) for linearly (circularly) polarized laser beam with increased intensity.
Spin-orbit, radial, and angular nonadiabatic matrix elements between the lowest excited states of NaRb are evaluated by quasi-relativistic ab initio methods, and the results accompanied by potential curves, permanent and transition moments are compared with experimental data and preceding calculations.
We investigate attosecond electron tunnelling dynamics in a time-resolved pump-probe experiment on the generation of higher-order harmonics that are emitted due to a stepwise plasma concentration change occurring with each half-cycle of the pump-field.
The squeezing of the atom in nonlinear interaction of a two-level atom with a single-mode field is investigated. The results show the nonlinearity plays an important role in entropy and variance squeezing of the atom.
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