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:cond-mat/0701446 · Laser Physics

Enhancing capacity of coherent optical information storage and transfer in a Bose-Einstein condensate

Özgür Esat Müstecaplıoğlu, D. Tarhan

Published Feb 1, 2007• 0 citations
arXivHTMLPDF

Abstract

The coherent optical information storage capacity of an atomic Bose-Einstein condensate is examined. The theory of slow light propagation in atomic clouds is generalized to the short-pulse regime by taking into account group velocity dispersion. It is shown that the number of stored pulses in the condensate can be optimized for a particular coupling laser power, temperature, and interatomic interaction strength. Analytical results are derived for a semi-ideal model of the condensate using the effective uniform density zone approximation. Detailed numerical simulations are also performed. It is found that the axial density profile of the condensate protects the pulse against group velocity dispersion. Furthermore, taking into account the finite radial size of the condensate, multimode light propagation in an atomic Bose-Einstein condensate is investigated. The number of modes that can be supported by a condensate is found. The single-mode condition is determined as a function of experimentally accessible parameters including trap size, temperature, condensate number density, and scattering length. Quantum coherent atom-light interaction schemes are proposed for enhancing multimode light propagation effects.

DOI
10.1134/s1054660x07020193

Related papers

Bose-Einstein yoğuşuk maddesinde optik bilgi kapasitesinin arttırılması

Devrim Tarhan, Nazmi Postacıoğlu, Özgür Esat Müstecaplıoğlu

Bose-Einstein condensates (BECs) have potential to be used in attractive applications. In particular, they have been thought to be suitable for being quantum optical dynamic memories to store coherent quantum optical information. In order to assess and enhance practical value of this proposal, we have performed various realistic examinations using detailed numerical and analytical methods. Firstly, propagation of short pulses of widths in microsecond to nanosecond range through the BEC has been considered. In this part, the influence of dispersion on the temporal characteristics and on the coherent optical information storage capacity is discussed. By modeling ultra-slow short pulses in the condensate under electromagnetically induced transparency (EIT) conditions, taking into account pulse broadening, we have determined optimum optical information storage capacity. Secondly, we have investigated conditions limiting the optimum number of optical modes that can be supported by an atomic BEC. In this part, in addition to EIT, a refractive index enhancement scheme was also considered, as it allows for accommodating many numbers of modes in the condensate. Furthermore, we have shown that multi-mode pulses, though less in number can also be realized at the cost of tolerable absorption in the case of EIT scheme. Secondly, we determine the number of optical modes supported by a wave guide in which refractive index enhancement is produced by an atomic BEC. Some analytical approximations have been made neglecting the spatial inhomogeneity. More accurate results have been obtained using a numerical model where the spatial inhomogeneity is taken into account. In the refractive index enhancement model, the predictions of (WKB) theory have been compared with those of fully numerical simulations. In this study, we investigate potential of atomic Bose-Einstein condensates as dynamic memory devices for coherent optical information processing. Specifically, the number of ultra-slow pulses that can be simultaneously present within the storage time in the condensate has been analyzed. By modeling short pulse propagation through the condensate, taking into account high-order dispersive properties, constraints on the information storage capacity has been discussed. The roles of temperature, spatial inhomogeneity, the interatomic interactions and the coupling laser on the pulse shape have been pointed out. For a restricted set of parameters, it has been found that coherent optical information storage capacity would be optimized. Coherent optical information storage capacity of an atomic Bose-Einstein condensate is examined. Theory of slow light propagation in atomic clouds is generalized to short pulse regime by taking into account group velocity dispersion. It is shown that the number of stored pulses in the condensate can be optimized for a particular coupling laser power, temperature and interatomic interaction strength. Analytical results are derived for semi-ideal model of the condensate using effective uniform density zone approximation. Detailed numerical simulations are also performed. It is found that axial density profile of the condensate protects the pulse against the group velocity dispersion. We examine the conditions determining the number of optical modes that can be supported by an atomic Bose-Einstein condensate. We show that under the conditions of refractive index enhancement via quantum coherence, it is possible to control the number of modes by means of experimentally accessible parameters including trap size, temperature, condensate number density and scattering lengths. Analytical results for the single and two-mode conditions are found. In order to slow down the group velocity we use electromagnetically induced transparency and find detuning parameter corresponding to number of modes. Results of numerical simulations are compared with analytical calculations of the propagation constants for a parabolic-refractive index profile. Furthermore, taking into account finite radial size of the condensate, multi-mode light propagation in atomic Bose-Einstein condensate is investigated. The number of modes that can be supported by a condensate is found. Single mode condition is determined as a function of experimentally accessible parameters including trap size, temperature, condensate number density and scattering length. Quantum coherent atom-light interaction schemes are proposed for enhancing multi-mode light propagation effects. Keywords: Optical memories, Coherent optical effects, Pulse shaping, and Bose-Einstein condensate.

•Dec 24, 2009•0 citations

Dispersive effects on optical information storage in Bose-Einstein condensates with ultraslow short pulses

Devrim Tarhan, Alphan Sennaroğlu, Özgür Esat Müstecaplıoğlu

We investigate the potential of atomic Bose-Einstein condensates as dynamic memory devices for coherent optical information processing. Specifically, the number of ultraslow pulses that can be simultaneously present within the storage time in the condensate has been analyzed. By modeling short-pulse propagation through the condensate, taking into account high-order dispersive properties, constraints on the information storage capacity are discussed. The roles of temperature, spatial inhomogeneity, the interatomic interactions, and the coupling laser on the pulse shape are pointed out. For a restricted set of parameters, it has been found that coherent optical information storage capacity would be optimized.

arXiv:cond-mat/0701325•Journal of the Optical Society of America B•Aug 31, 2006•6 citations

Ultraslow optical modes in Bose-Einstein condensates

Özgür Esat Müstecaplıoğlu, Devrim Tarhan

Light can be slowed down to ultraslow speeds v ia electromagnetically induced transparency in atomic Bose-Einstein condensates. This is thought to be useful for storage of quantum information for weak probe pulses. We investigate the effects of inhomogeneous density profile of the condensate on propagation of such ultraslow pulses. We find that spatial density of an atomic condensate leads to a graded refractive index profile, for an off-resonant probe pulse when condensate parameters are suitably chosen. Within the window of negligible absorption, conditions for degenerate multiple waveguide modes are determined. Both analytical and numerical studies are presented to reveal the effects of experimentally controllable parameters, such as temperature and interatomic interaction strength on the number of modes. Group velocity dispersion and modal dispersion are discussed. The effect of waveguide dispersion, in addition to usual material dispersion, on ultraslow pulses is pointed out.

Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE•May 18, 2007•0 citations

Storing and processing optical information with ultraslow light in Bose-Einstein condensates

Zachary Dutton, Lene Vestergaard Hau

We theoretically explore coherent information transfer between ultraslow light pulses and Bose-Einstein condensates (BEC's) and find that storing light pulses in BEC's allows the coherent condensate dynamics to process optical information. We consider BEC's of alkali atoms with a $\ensuremath{\Lambda}$ energy level configuration. In this configuration, one laser (the coupling field) can cause a pulse of a second pulsed laser (the probe field) to propagate with little attenuation (electromagnetically induced transparency) at a very slow group velocity $(\ensuremath{\sim}10\phantom{\rule{0.3em}{0ex}}\mathrm{m}∕\mathrm{s})$ and be spatially compressed to lengths smaller than the BEC. These pulses can be fully stopped and later revived by switching the coupling field off and on. Here we develop a formalism, applicable in both the weak- and strong-probe regimes, to analyze such experiments and establish several results: (1) We show that the switching can be performed on time scales much faster than the adiabatic time scale for electromagnetically induced transparancy even in the strong-probe regime. We also study the behavior of the system changes when this time scale is faster than the excited state lifetime. (2) Stopped light pulses write their phase and amplitude information onto spatially dependent atomic wave functions, resulting in coherent two-component BEC dynamics during long storage times. We investigate examples relevant to $^{87}\mathrm{Rb}$ experimental parameters and see a variety of novel dynamics occur, including interference fringes, gentle breathing excitations, and two-component solitons, depending on the relative scattering lengths of the atomic states used and the probe to coupling intensity ratio. We find that the dynamics when the levels $\ensuremath{\mid}F=1,{M}_{F}=\ensuremath{-}1⟩$ and $\ensuremath{\mid}F=2,{M}_{F}=+1⟩$ are used could be well suited to designing controlled processing of the information input on the probe. (3) Switching the coupling field on after the dynamics writes the evolved BEC wave functions density and phase features onto a revived probe pulse, which then propagates out. We establish equations linking the BEC wave function to the resulting output probe pulses in both the strong- and weak-probe regimes. We then identify sources of deviations from these equations due to absorption and distortion of the pulses. These deviations result in imperfect fidelity of the information transfer from the atoms to the light fields and we calculate this fidelity for Gaussian-shaped features in the BEC wave functions. In the weak-probe case, we find that the fidelity is affected both by absorption of very-small-length-scale features and absorption of features occupying regions near the condensate edge. We discuss how to optimize the fidelity using these considerations. In the strong-probe case, we find that when the oscillator strengths for the two transitions are equal the fidelity is not strongly sensitive to the probe strength, while when they are unequal the fidelity is worse for stronger probes. Applications to distant communication between BEC's, squeezed light generation, and quantum information are anticipated.

arXiv:quant-ph/0404018•Physical Review A•Nov 30, 2004•68 citations

Propagation of short pulses through a Bose-Einstein condensate

Devrim Tarhan, Seçkin Şefi, Özgür Esat Müstecaplıoğlu

We study propagation of short laser pulses in a Bose-Einstein condensate taking into account dispersive effects under the conditions for electromagnetically induced transparency. We calculate dispersion coefficients using typical experimental parameters of slow-light schemes in condensates. By numerically propagating the laser pulse, and referring to theoretical estimations, we determine the conditions for which dispersion starts to introduce distortions on the pulse shape.

arXiv:cond-mat/0701390•Journal of Physics Conference Series•Apr 1, 2006•1 citation

Laser pulse amplification and dispersion compensation in an effectively extended optical cavity containing Bose–Einstein condensates

D Tarhan, Alphan Sennaroğlu, Özgür Esat Müstecaplıoğlu

We review and critically evaluate our proposal of a pulse amplification scheme based on two Bose-Einstein condensates inside the resonator of a mode-locked laser. Two condensates are used for compensating the group velocity dispersion. Ultraslow light propagation through the condensate leads to a considerable increase in the cavity round-trip delay time, lowers the effective repetition rate of the laser, and hence scales up the output pulse energy. It has been recently argued that atom-atom interactions would make our proposal even more efficient. However, neither in our original proposal nor in the case of interactions, limitations due to heating of the condensates by optical energy absorption were taken into account. Our results show that there is a critical time of operation, $~0.3$ ms, for the optimal amplification factor, which is in the order of $\sim 10^2$ at effective condensate lengths in the order of $\sim 50$ $μ$m. The bandwidth limitation of the amplifier on the minimum temporal width of the pulse that can be amplified with this technique is also discussed.

arXiv:1301.1849•Journal of Physics B Atomic Molecular and Optical Physics•Dec 10, 2012•1 citation
The coherent optical information storage capacity of an atomic Bose-Einstein condensate is examined. The theory of slow light propagation in atomic clouds is generalized to the short-pulse regime by taking into account group velocity dispersion. It is shown that the number of stored pulses in the condensate can be optimized for a particular coupling laser power, temperature, and interatomic interaction strength. Analytical results are derived for a semi-ideal model of the condensate using the effective uniform density zone approximation. Detailed numerical simulations are also performed. It is found that the axial density profile of the condensate protects the pulse against group velocity dispersion. Furthermore, taking into account the finite radial size of the condensate, multimode light propagation in an atomic Bose-Einstein condensate is investigated. The number of modes that can be supported by a condensate is found. The single-mode condition is determined as a function of experimentally accessible parameters including trap size, temperature, condensate number density, and scattering length. Quantum coherent atom-light interaction schemes are proposed for enhancing multimode light propagation effects.
Bose-Einstein condensates (BECs) have potential to be used in attractive applications. In particular, they have been thought to be suitable for being quantum optical dynamic memories to store coherent quantum optical information. In order to assess and enhance practical value of this proposal, we have performed various realistic examinations using detailed numerical and analytical methods. Firstly, propagation of short pulses of widths in microsecond to nanosecond range through the BEC has been considered. In this part, the influence of dispersion on the temporal characteristics and on the coherent optical information storage capacity is discussed. By modeling ultra-slow short pulses in the condensate under electromagnetically induced transparency (EIT) conditions, taking into account pulse broadening, we have determined optimum optical information storage capacity. Secondly, we have investigated conditions limiting the optimum number of optical modes that can be supported by an atomic BEC. In this part, in addition to EIT, a refractive index enhancement scheme was also considered, as it allows for accommodating many numbers of modes in the condensate. Furthermore, we have shown that multi-mode pulses, though less in number can also be realized at the cost of tolerable absorption in the case of EIT scheme. Secondly, we determine the number of optical modes supported by a wave guide in which refractive index enhancement is produced by an atomic BEC. Some analytical approximations have been made neglecting the spatial inhomogeneity. More accurate results have been obtained using a numerical model where the spatial inhomogeneity is taken into account. In the refractive index enhancement model, the predictions of (WKB) theory have been compared with those of fully numerical simulations. In this study, we investigate potential of atomic Bose-Einstein condensates as dynamic memory devices for coherent optical information processing. Specifically, the number of ultra-slow pulses that can be simultaneously present within the storage time in the condensate has been analyzed. By modeling short pulse propagation through the condensate, taking into account high-order dispersive properties, constraints on the information storage capacity has been discussed. The roles of temperature, spatial inhomogeneity, the interatomic interactions and the coupling laser on the pulse shape have been pointed out. For a restricted set of parameters, it has been found that coherent optical information storage capacity would be optimized. Coherent optical information storage capacity of an atomic Bose-Einstein condensate is examined. Theory of slow light propagation in atomic clouds is generalized to short pulse regime by taking into account group velocity dispersion. It is shown that the number of stored pulses in the condensate can be optimized for a particular coupling laser power, temperature and interatomic interaction strength. Analytical results are derived for semi-ideal model of the condensate using effective uniform density zone approximation. Detailed numerical simulations are also performed. It is found that axial density profile of the condensate protects the pulse against the group velocity dispersion. We examine the conditions determining the number of optical modes that can be supported by an atomic Bose-Einstein condensate. We show that under the conditions of refractive index enhancement via quantum coherence, it is possible to control the number of modes by means of experimentally accessible parameters including trap size, temperature, condensate number density and scattering lengths. Analytical results for the single and two-mode conditions are found. In order to slow down the group velocity we use electromagnetically induced transparency and find detuning parameter corresponding to number of modes. Results of numerical simulations are compared with analytical calculations of the propagation constants for a parabolic-refractive index profile. Furthermore, taking into account finite radial size of the condensate, multi-mode light propagation in atomic Bose-Einstein condensate is investigated. The number of modes that can be supported by a condensate is found. Single mode condition is determined as a function of experimentally accessible parameters including trap size, temperature, condensate number density and scattering length. Quantum coherent atom-light interaction schemes are proposed for enhancing multi-mode light propagation effects. Keywords: Optical memories, Coherent optical effects, Pulse shaping, and Bose-Einstein condensate.
We investigate the potential of atomic Bose-Einstein condensates as dynamic memory devices for coherent optical information processing. Specifically, the number of ultraslow pulses that can be simultaneously present within the storage time in the condensate has been analyzed. By modeling short-pulse propagation through the condensate, taking into account high-order dispersive properties, constraints on the information storage capacity are discussed. The roles of temperature, spatial inhomogeneity, the interatomic interactions, and the coupling laser on the pulse shape are pointed out. For a restricted set of parameters, it has been found that coherent optical information storage capacity would be optimized.
Light can be slowed down to ultraslow speeds v ia electromagnetically induced transparency in atomic Bose-Einstein condensates. This is thought to be useful for storage of quantum information for weak probe pulses. We investigate the effects of inhomogeneous density profile of the condensate on propagation of such ultraslow pulses. We find that spatial density of an atomic condensate leads to a graded refractive index profile, for an off-resonant probe pulse when condensate parameters are suitably chosen. Within the window of negligible absorption, conditions for degenerate multiple waveguide modes are determined. Both analytical and numerical studies are presented to reveal the effects of experimentally controllable parameters, such as temperature and interatomic interaction strength on the number of modes. Group velocity dispersion and modal dispersion are discussed. The effect of waveguide dispersion, in addition to usual material dispersion, on ultraslow pulses is pointed out.
We theoretically explore coherent information transfer between ultraslow light pulses and Bose-Einstein condensates (BEC's) and find that storing light pulses in BEC's allows the coherent condensate dynamics to process optical information. We consider BEC's of alkali atoms with a $\ensuremath{\Lambda}$ energy level configuration. In this configuration, one laser (the coupling field) can cause a pulse of a second pulsed laser (the probe field) to propagate with little attenuation (electromagnetically induced transparency) at a very slow group velocity $(\ensuremath{\sim}10\phantom{\rule{0.3em}{0ex}}\mathrm{m}∕\mathrm{s})$ and be spatially compressed to lengths smaller than the BEC. These pulses can be fully stopped and later revived by switching the coupling field off and on. Here we develop a formalism, applicable in both the weak- and strong-probe regimes, to analyze such experiments and establish several results: (1) We show that the switching can be performed on time scales much faster than the adiabatic time scale for electromagnetically induced transparancy even in the strong-probe regime. We also study the behavior of the system changes when this time scale is faster than the excited state lifetime. (2) Stopped light pulses write their phase and amplitude information onto spatially dependent atomic wave functions, resulting in coherent two-component BEC dynamics during long storage times. We investigate examples relevant to 87Rb^{87}\mathrm{Rb}87Rb experimental parameters and see a variety of novel dynamics occur, including interference fringes, gentle breathing excitations, and two-component solitons, depending on the relative scattering lengths of the atomic states used and the probe to coupling intensity ratio. We find that the dynamics when the levels $\ensuremath{\mid}F=1,{M}_{F}=\ensuremath{-}1⟩$ and $\ensuremath{\mid}F=2,{M}_{F}=+1⟩$ are used could be well suited to designing controlled processing of the information input on the probe. (3) Switching the coupling field on after the dynamics writes the evolved BEC wave functions density and phase features onto a revived probe pulse, which then propagates out. We establish equations linking the BEC wave function to the resulting output probe pulses in both the strong- and weak-probe regimes. We then identify sources of deviations from these equations due to absorption and distortion of the pulses. These deviations result in imperfect fidelity of the information transfer from the atoms to the light fields and we calculate this fidelity for Gaussian-shaped features in the BEC wave functions. In the weak-probe case, we find that the fidelity is affected both by absorption of very-small-length-scale features and absorption of features occupying regions near the condensate edge. We discuss how to optimize the fidelity using these considerations. In the strong-probe case, we find that when the oscillator strengths for the two transitions are equal the fidelity is not strongly sensitive to the probe strength, while when they are unequal the fidelity is worse for stronger probes. Applications to distant communication between BEC's, squeezed light generation, and quantum information are anticipated.
We review and critically evaluate our proposal of a pulse amplification scheme based on two Bose-Einstein condensates inside the resonator of a mode-locked laser. Two condensates are used for compensating the group velocity dispersion. Ultraslow light propagation through the condensate leads to a considerable increase in the cavity round-trip delay time, lowers the effective repetition rate of the laser, and hence scales up the output pulse energy. It has been recently argued that atom-atom interactions would make our proposal even more efficient. However, neither in our original proposal nor in the case of interactions, limitations due to heating of the condensates by optical energy absorption were taken into account. Our results show that there is a critical time of operation,  0.3~0.3 0.3 ms, for the optimal amplification factor, which is in the order of ∼102\sim 10^2∼102 at effective condensate lengths in the order of ∼50\sim 50∼50 μμμm. The bandwidth limitation of the amplifier on the minimum temporal width of the pulse that can be amplified with this technique is also discussed.