Abstract: Herein, we propose a scheme for the realization of two-dimensional atomic localization in a λ-type three-level atomic medium such that the atom interacts with the two orthogonal standing-wave fields and a probe field. Because of the spatially dependent atom-field interaction, the information about the position of the atom can be obtained by monitoring the probe transmission spectra of the weak probe field for the first time. A single and double sharp localized peaks are observed in the one-wavelength domain. We have theoretically archived high-resolution and high-precision atomic localization within a region smaller than λ/25 × λ/25. The results may have potential applications in the field of nano-lithography and advance laser cooling technology.

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Topics: Transmission (telecommunications) (58%)

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7 results found

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01 Jan 1993-

Abstract: Abstract As early as 1917, Einstein had predicted that momentum is transferred in the absorption and emission of light, but it was not until the 1980's that such optical momentum transfer was used to cool and trap neutral atoms. By properly tuning laser light close to atomic transitions, atomic samples can be cooled to extremely low temperatures, the brightness of atomic beams can be enhanced to unprecedented values, and atoms can be manipulated with extraordinary precision. In this review several of the techniques for laser cooling and trapping of neutral atoms are described.

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Topics: Wave function (54%), Charged particle (52%), Monte Carlo method (51%) ... show more

142 Citations

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Muhammad Khan^{1}, Muhammad Idrees^{2}, Muhammad Idrees^{3}, Bakth Amin Bacha^{2} +2 more•Institutions (3)

Abstract: The control and modification of divergence angle and birefringent rotary photon drags under the effect of quantum tunnelling is investigated in this article. The circularly birefringence Δn=nr(+)−nr(−) , divergence angle θ d and rotary photon dragging angles θr(±) are found to have modified with the strength of tunnelling frequencies. The left and right circularly polarized beams show superlominality of group velocities −c/150 and −c/50, respectively, and the divergence angle of 0.050 radian per increment of tunnelling frequency. The maximum of rotary photon drags for both beams is measured θr(±)=±2 micro radian with fractional change of 2%. The output pulses intensities ∣Eout+(t)∣2 and ∣Eout−(t)∣2 show uniform undistorted shapes with tunnelling frequencies and no energy losses. The results could have significant applications in the fields of quantum optics, photonics, plasmonics and special mode imaging coding technology.

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Topics: Quantum tunnelling (51%)

5 Citations

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Muhammad Idrees^{1}, Muhammad Idrees^{2}, Muhib Ullah^{1}, Bakth Amin Bacha^{2} +2 more•Institutions (2)

Abstract: The two-dimensional (2D) atomic localization is theoretically investigated via tunable surface plasmon polaritons (SPPs), generated on the metal (Ag) surface coupled to a quantum coherent three-level $$\lambda$$
-type medium (
$$^{87}$$
Rb) embedded as a dielectric host. Such a useful scheme for highly precise atomic localization is reported by using the absorption spectrum of SPPs. Owing to space-dependent light–matter interaction, the sharp localized peaks are observed in a single wavelength domain of 2D space with maximum probability. By properly varying the system parameters, the precision and numbers of the localized peaks are controlled. Consequently, highly efficient and high-resolution atomic localization can be achieved in a region smaller than $$\lambda /20\times \lambda /20$$
. The spatial resolution of atomic localization is greatly improved as compared to the previously studied cases. These results may have potential useful applications in the fields of quantum nanoplasmonics, nanolithography, and nanophotonics.

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Topics: Surface plasmon polariton (57%), Nanophotonics (55%)

4 Citations

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Abstract: Surface plasmon polaritons are investigated at the interface of cesium atomic medium and silver-silica nano-composite. The polaritons rotary drag at the propagation length and penetration depth is significantly modified. The ratio of the wavelengths of surface plasmon polaritons and the free space electromagnetic waves are nearly 0.5810. The group velocity of plasmon polaritons is higher than the speed of light and is ranging from $$-6\times 10^9$$
to $$1\times 10^{10}$$
which shows higher superluminality in a small propagation length. The penetration depths of polaritons in cesium and nano-composite are $$1.5\times 10^{-10}m$$
and $$2\times 10^{-7}m$$
and vary with strength of the control fields. The rotary plasmon polaritons drag is in the rang of $$\pm 50$$
to $$\pm 60$$
nano radian at the propagation length of polaritons. The rotary plasmon polartions drag at the penetration depths of the atomic and the silver nano-composite media is noted in the range of $$\pm 10$$
atto radian and $$\pm 10$$
femto radian respectively. The results may find applications in modifying the sensor coding technology.

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Topics: Surface plasmon polariton (60%), Plasmon (54%), Polariton (54%) ... show more

1 Citations

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Hayatullah^{1}, Muhammad Idrees^{2}, Muhammad Idrees^{3}, Bakth Amin Bacha^{3} +2 more•Institutions (3)

Abstract: The Gain assisted medium is being investigated to modify the rotary photon drag with the phase and angular momentum of the photon. Significant gain doublets and normal/anomalous dispersion with high subliminal/superluminal are controlled and modified by the angular quantum number and phase of angular momentum of the probe beam. Parameters of pump and control and angular momentum of probe fields enhanced photon drag from micro radian to milli radian. A $$\pm\,5$$
micro radian drag is tune to $$\pm\, 100$$
milli radian with these parameters. The rotary photon drag show large fluctuation with phase and quantum number of angular momentum of probe beam. The rotary photon drag is greatly improved as compared to the previously studied cases. The work is useful for advancing the technologies of position control, phase matching conditions and special modes of imaging coding.

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Topics: Angular momentum (58%), Azimuthal quantum number (56%), Radian (56%) ... show more

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67 results found

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Abstract: The basic physical effects leading to radiation-induced forces are reviewed. A simple derivation of the mathematical expressions for the classical light forces is given. The influence of quantum fluctuations is demonstrated and the possibilities for trapping neutral particles are discussed. Two recent successful laser cooling and trapping experiments are described to illustrate the applications of the basic principles.

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Topics: Resolved sideband cooling (57%), Laser cooling (57%), Doppler cooling (54%) ... show more

1,236 Citations

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Agedi N. Boto^{1}, Danial S. Abrams^{1}, Colin P. Williams^{1}, Jonathan P. Dowling^{1}•Institutions (1)

12 May 2000-

Abstract: Summary form only given. It has been known for some time that entangled photon pairs, such as generated by spontaneous parametric down conversion, have unusual imaging characteristics with sub-shot-noise interferometric phase measurement. In fact, Fonseca, et al., recently demonstrated resolution of a two-slit diffraction patterned at half the Rayleigh limit in a coincidence counting experiment. What we show is that this type of effect is possible not only in coincidence counting experiments, but also in real two-photon absorbing systems, such as those used in classical interferometric lithography. In particular, we will demonstrate that quantum entanglement is the resource that allows sub-diffraction limited lithography.

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Topics: Quantum lithography (66%), Coincidence counting (62%), Spontaneous parametric down-conversion (58%) ... show more

1,153 Citations

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Abstract: We measure the Kerr-nonlinear index of refraction of a three-level Lambda-type atomic system inside an optical ring cavity. The Kerr nonlinearity is modified and greatly enhanced near atomic resonant conditions for both probe and coupling beams. The Kerr nonlinear coefficient n(2) changes sign when the coupling beam frequency detuning switches sign, which can lead to interesting applications in optical devices such as all-optical switches.

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Topics: Kerr effect (63%), Atomic coherence (61%), Refraction (52%) ... show more

376 Citations

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Abstract: We perform a time-dependent analysis of four-wave mixing (FWM) in a double-$\ensuremath{\Lambda}$ system in an ultraslow-propagation regime and obtain the analytical expressions of pulsed probe laser, FWM-generated pulse, phase shifts and absorption coefficients, group velocities, and FWM efficiency. With these analytical expressions, we show that an efficiently generated FWM field can acquire the same ultraslow group velocity $({V}_{g}∕c\ensuremath{\sim}{10}^{\ensuremath{-}4}--{10}^{\ensuremath{-}5})$ and pulse shape of a probe pump and that the maximum FWM efficiency is greater than 25%, which is orders of magnitude larger than previous FWM schemes in the ultraslow-propagation regime.

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Topics: Absorption (logic) (57%), Four-wave mixing (52%)

376 Citations