Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

arXiv:1408.4007 · Journal of the Optical Society of America B

Optical trap potential control in N-type four-level atoms by femtosecond Gaussian pulses

Subhadeep Chakraborty, Amarendra K. Sarma

Published Jan 13, 2015• 6 citations
arXivHTMLPDF

Abstract

In this work, we present a scheme to control the optical dipole trap potential in an N-type four-level atomic system by using chirped femtosecond Gaussian pulses. The spatial size of the trap can be well controlled by tuning the beam waist of the Gaussian pulse and the detuning frequency. The trapping potential splits with increasing Rabi frequency about the center of the trap, a behavior analogous to the one observed experimentally in the context of trapping nanoparticles with femtosecond pulses. An attempt is made to explain the physics behind this phenomenon by studying the spatial probability distribution of the atomic populations.

DOI
10.1364/josab.32.000270

Related papers

Trap split with Laguerre-Gaussian beams

Seyedeh Hamideh Kazemi, Saeed Ghanbari, Mohammad Mahmoudi

Abstract We present a convenient and effective way to generate a novel phenomenon of trapping, named ‘trap split’, in a conventional four-level double-Λ atomic system, driven by four femtosecond Laguerre-Gaussian laser pulses. We find that trap split can always be achieved when atoms are trapped by such laser pulses, as compared to Gaussian ones. This feature is enabled by the interaction of the atomic system and the Laguerre-Gaussian laser pulses with zero intensity in the center. A further advantage of using Laguerre-Gaussian laser pulses is the insensitivity to fluctuation in the intensity of the lasers in such a way that the separation between the traps remains constant. Moreover, it is demonstrated that the suggested scheme with Laguerre-Gaussian laser pulses can form optical traps with spatial sizes that are not limited by the wavelength of the laser, and can, in principle, become smaller than the wavelength of light. This work would greatly facilitate the trapping and manipulating of particles and the generation of trap split. It may also suggest the possibility of extension into new research fields, such as micro-machining and biophysics.

arXiv:1610.07209•Journal of Optics•May 24, 2017•10 citations

Phase-controlled optical trap potential in a closed-loop atomic system

Seyedeh Hamideh Kazemi, Mohammad Mahmoudi

The optical trap potential is studied in a four-level double-Λ closed-loop atomic system in the multiphoton resonance condition. We apply four femtosecond Gaussian laser beams to generate a closed-loop configuration. It is shown that the induced optical dipole force on the system dramatically depends on the relative phase of applied fields, and it switches from focusing to defocusing in the transverse direction, simply by properly changing the relative phase. Through special switching of the relative phase, the trapping potential splits into two positions, which has novel applications in trapping and manipulating the particles. Moreover, it is further demonstrated that trap depth can be manipulated by the relative phase. Finally, a maximum coherent population transfer is achieved for a special value of the relative phase of applied fields.

Journal of the Optical Society of America B•Feb 25, 2016•9 citations

Coherent population transfer and optical dipole force by chirped Gaussian femtosecond pulses in four level 87Rb

Subhadeep Chakraborty, Amarendra K. Sarma

We report coherent population transfer(CPT) in a four level atomic system, coupled by three chirped Gaussian femtosecond pulses. CPT is studied under two specific conditions beyond the RWA. It is observed that nearly complete population transfer to the states |3> and |4> can be achieved by maintaining proper resonance condition and judiciously choosing the laser parameters. In addition to this, the transverse optical dipole force on the four-level atomic system is numerically studied. The transverse force provides an acceleration to an atom which is eight order of magnitude higher than earth’s gravitational acceleration g. The force changes from a focusing force to a defocusing one as the initial population changes from the ground states to the excited states.

AIP conference proceedings•Jan 1, 2014•0 citations

Simultaneous control of optical dipole force and coherence creation by super-Gaussian femtosecond pulses in Λ -like atomic systems

Pawan Kumar, Parvendra Kumar, Amarendra K. Sarma

We report a study of the optical dipole force on a beam of neutral three-level, $\ensuremath{\Lambda}$-like atomic system induced by a femtosecond super-Gaussian pulse. We show that maximum coherence between the ground state $|1\ensuremath{\rangle}$ and the excited state $|2\ensuremath{\rangle}$ could be achieved using a train of femtosecond pulses. In addition, it is possible to control the trajectory of the atoms in an atomic beam by using the same scheme. The robustness of the scheme against the variation of the pulse parameters is also investigated.

arXiv:1310.8142•Physical Review A•Mar 19, 2014•12 citations

Femtosecond Stark-Chirped Rapid Adiabatic Passage by Single Spectrally Shaped Pulse

Han-gyeol Lee, Hyosub Kim, Hanlae Jo +1 more

Complete population inversion of two-level atoms in a magneto-optical trap is demonstrated by off-resonant two laser pulses shaped from a single ultrafast laser pulse. The observed phenomenon is explained in the context of femto-second laser version of Stark-chirped rapid adiabatic passage.

•Jan 1, 2015•0 citations

Ultrafast population transfer in a three-level system driven by the chirped Gauss femtosecond pulse

Fan Xi-jun

The ultrafast particle population transfer in a ■-type three-level atomic system driven by linearly polarized chirped Gauss femtosecond laser pulse is investigated by using numerical solution of the Schrdinger equation without the rotating wave approximation(RWA).It is shown that the population transfer is mainly determined by the Rabi frequency(intensity) of the driving laser field and chirp rate,and the ratio of two dipole moments and the pulse width also have obvious effect on the population transfer.By choosing suitable values of the above parameters,nearly complete population transfer(99.6%) can be realized.

Journal of Optoelectronics·laser•Jan 1, 2010•0 citations
In this work, we present a scheme to control the optical dipole trap potential in an N-type four-level atomic system by using chirped femtosecond Gaussian pulses. The spatial size of the trap can be well controlled by tuning the beam waist of the Gaussian pulse and the detuning frequency. The trapping potential splits with increasing Rabi frequency about the center of the trap, a behavior analogous to the one observed experimentally in the context of trapping nanoparticles with femtosecond pulses. An attempt is made to explain the physics behind this phenomenon by studying the spatial probability distribution of the atomic populations.
Abstract We present a convenient and effective way to generate a novel phenomenon of trapping, named ‘trap split’, in a conventional four-level double-Λ atomic system, driven by four femtosecond Laguerre-Gaussian laser pulses. We find that trap split can always be achieved when atoms are trapped by such laser pulses, as compared to Gaussian ones. This feature is enabled by the interaction of the atomic system and the Laguerre-Gaussian laser pulses with zero intensity in the center. A further advantage of using Laguerre-Gaussian laser pulses is the insensitivity to fluctuation in the intensity of the lasers in such a way that the separation between the traps remains constant. Moreover, it is demonstrated that the suggested scheme with Laguerre-Gaussian laser pulses can form optical traps with spatial sizes that are not limited by the wavelength of the laser, and can, in principle, become smaller than the wavelength of light. This work would greatly facilitate the trapping and manipulating of particles and the generation of trap split. It may also suggest the possibility of extension into new research fields, such as micro-machining and biophysics.
The optical trap potential is studied in a four-level double-Λ closed-loop atomic system in the multiphoton resonance condition. We apply four femtosecond Gaussian laser beams to generate a closed-loop configuration. It is shown that the induced optical dipole force on the system dramatically depends on the relative phase of applied fields, and it switches from focusing to defocusing in the transverse direction, simply by properly changing the relative phase. Through special switching of the relative phase, the trapping potential splits into two positions, which has novel applications in trapping and manipulating the particles. Moreover, it is further demonstrated that trap depth can be manipulated by the relative phase. Finally, a maximum coherent population transfer is achieved for a special value of the relative phase of applied fields.
We report coherent population transfer(CPT) in a four level atomic system, coupled by three chirped Gaussian femtosecond pulses. CPT is studied under two specific conditions beyond the RWA. It is observed that nearly complete population transfer to the states |3> and |4> can be achieved by maintaining proper resonance condition and judiciously choosing the laser parameters. In addition to this, the transverse optical dipole force on the four-level atomic system is numerically studied. The transverse force provides an acceleration to an atom which is eight order of magnitude higher than earth’s gravitational acceleration g. The force changes from a focusing force to a defocusing one as the initial population changes from the ground states to the excited states.
We report a study of the optical dipole force on a beam of neutral three-level, $\ensuremath{\Lambda}$-like atomic system induced by a femtosecond super-Gaussian pulse. We show that maximum coherence between the ground state $|1\ensuremath{\rangle}$ and the excited state $|2\ensuremath{\rangle}$ could be achieved using a train of femtosecond pulses. In addition, it is possible to control the trajectory of the atoms in an atomic beam by using the same scheme. The robustness of the scheme against the variation of the pulse parameters is also investigated.
The ultrafast particle population transfer in a ■-type three-level atomic system driven by linearly polarized chirped Gauss femtosecond laser pulse is investigated by using numerical solution of the Schrdinger equation without the rotating wave approximation(RWA).It is shown that the population transfer is mainly determined by the Rabi frequency(intensity) of the driving laser field and chirp rate,and the ratio of two dipole moments and the pulse width also have obvious effect on the population transfer.By choosing suitable values of the above parameters,nearly complete population transfer(99.6%) can be realized.