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

Europhysics Letters (EPL)

Self-distributed feedback lasing in a system of cold atoms

Brian W J McNeil, Gordon R. M. Robb, R. Bonifacio, N. Piovella

Published Feb 1, 2000• 2 citations
Publisher

Abstract

We present a semiclassical analysis of lasing with an injected signal in a system of cold two-level atoms where the effects of atomic recoil are included self-consistently. This analysis predicts that the atoms may bunch under the effects of dipole forces to produce a density grating. This grating produces distributed feedback which can induce lasing action even when the gain of the atomic medium is less than the cavity losses.

DOI
10.1209/epl/i2000-00151-4

Related papers

Self-Organization, Broken Symmetry, and Lasing in an Atomic Vapor: The Interdependence of Gratings and Gain

Philip Hemmer, N. P. Bigelow, D. P. Katz +3 more

We describe a novel optical gain mechanism observed in a strongly driven Doppler-broadened atomic vapor. Gain and self-stabilizing laser oscillations are observed in a direction which is counterpropagating with respect to the traveling wave pump. Using Bragg diffraction, we show that the underlying gain-lasing mechanism is directly tied to a spontaneously formed optical wavelength grating. We suggest that this grating arises from a self-organization or self-bunching of the atoms, an effect which is mediated by recoil just as in the free electron laser.

Physical Review Letters•Aug 19, 1996•84 citations

Recoil-induced lasing

J. Javaloyes, M. Perrin, Gian Luca Lippi +1 more

The interaction of an atomic gas confined inside a cavity with a strong electromagnetic field is numerically and theoretically investigated in a regime where recoil effects are not negligible. The spontaneous appearance of a density grating (atomic bunching) accompanied by the onset of coherent backpropagation is found to be ruled by a continuous phase-transition. Numerical tests allow us to convincingly prove that the transition is steered by the appearence of a periodic atomic density modulation. Consideration of different experimental relaxation mechanisms induces us to analyze the problem in nearly analytic form, in the large detuning limit, using both a Vlasov approach and a Fokker-Planck description. The application of our predictions to recent experimental findings, reported in [Phys. Rev. Lett. {\bf 91}, 183601 (2003)], yields a semi-quantitative agreement with the observations.

arXiv:physics/0311132•Nov 27, 2003•0 citations

Recoil-induced lasing of cold atoms

Péter Horák, Klaus M. Gheri, Helmut Ritsch

We present a review and extension of a recently made proposal [K. M. Gheri et al., Phys. Rev. Lett. 74, 678 (1995)] to utilize cold atoms in a Raman configuration as a uv-laser gain medium in the limit of the photon recoil shift exceeding the natural atomic linewidth and the Doppler broadening. A discussion of model assumptions is given as well as an analysis of the dependence of the gain on detunings and decay rates. Special emphasis is put on a calculation of the nonlinear gain that allows a self-consistent determination of the uv-laser intensity as a function of the model parameters. For a deep uv transition, the gain turns out to be of approximately the same order of magnitude as for comparable optical transitions including a significant enhancement through Raman coherences especially at weak laser intensities. Our calculations suggest the possibility of a cw deep uv laser, based on laser cooled metastable (e.g., helium) atoms.

Physical Review A•Jul 1, 1995•10 citations

Two-Photon Collective Atomic Recoil Lasing

James McKelvie, Gordon R. M. Robb

We present a theoretical study of the interaction between light and a cold gasof three-level, ladder configuration atoms close to two-photon resonance. In particular, weinvestigate the existence of collective atomic recoil lasing (CARL) instabilities in differentregimes of internal atomic excitation and compare to previous studies of the CARL instabilityinvolving two-level atoms. In the case of two-level atoms, the CARL instability is quenchedat high pump rates with significant atomic excitation by saturation of the (one-photon)coherence, which produces the optical forces responsible for the instability and rapid heatingdue to high spontaneous emission rates. We show that in the two-photon CARL schemestudied here involving three-level atoms, CARL instabilities can survive at high pump rateswhen the atoms have significant excitation, due to the contributions to the optical forces frommultiple coherences and the reduction of spontaneous emission due to transitions betweenthe populated states being dipole forbidden. This two-photon CARL scheme may form thebasis of methods to increase the effective nonlinear optical response of cold atomic gases.

Atoms•Nov 20, 2015•0 citations

Lasing and cooling in a finite-temperature cavity

Thomas Salzburger, Helmut Ritsch

We present a microscopic laser model for many atoms coupled to a single-cavity mode, including the light forces, which result from atom-field momentum exchange. Within a semiclassical description, we solve the equations for the atomic motion and the internal dynamics to obtain analytic expressions for the optical potential and the friction force seen by each atom. When optical gain is maximum at frequencies where the light field extracts kinetic energy from the atomic motion, the dynamics combines optical lasing and motional cooling. From the corresponding momentum-diffusion coefficient we predict sub-Doppler temperatures in the stationary state. This generalizes the theory of cavity-enhanced laser cooling to active cavity systems. We identify the gain-induced reduction of the effective resonator linewidth as the key origin for the faster cooling and the lower temperatures, which implies that a bad cavity with a gain medium can replace a high-$Q$ cavity. In addition, this shows the importance of light forces for gas lasers in the low-temperature limit, where atoms can arrange in a periodic pattern maximizing gain and counteracting spatial hole burning. Ultimately, in the low-temperature limit, such a setup should allow us to combine optical lasing and atom lasing in a single device.

arXiv:quant-ph/0603185•Physical Review A•Sep 11, 2006•13 citations

Recoil-induced effects in absorptive optical bistability

R. Bonifacio, Brian W J McNeil, N. Piovella +1 more

We present an analysis of absorptive optical bistability in a system of cold atoms enclosed in a bidirectional ring cavity. This analysis is carried out using a system of equations that extends the so-called Maxwell-Bloch model to self-consistently include atomic center-of-mass motion. The analysis predicts an instability resulting in the simultaneous generation of an atomic density grating and a coherently backscattered radiation field. The formation of the density grating arises from a modulation of the radiation pressure forces exerted on the atoms. A consequence of this instability is that the lower transmission branch of the usual bistability curve, where atomic motion is neglected, can become unstable and the system switches to the upper transmission branch destroying the bistability.

Physical Review A•Jan 7, 2000•5 citations
We present a semiclassical analysis of lasing with an injected signal in a system of cold two-level atoms where the effects of atomic recoil are included self-consistently. This analysis predicts that the atoms may bunch under the effects of dipole forces to produce a density grating. This grating produces distributed feedback which can induce lasing action even when the gain of the atomic medium is less than the cavity losses.
We describe a novel optical gain mechanism observed in a strongly driven Doppler-broadened atomic vapor. Gain and self-stabilizing laser oscillations are observed in a direction which is counterpropagating with respect to the traveling wave pump. Using Bragg diffraction, we show that the underlying gain-lasing mechanism is directly tied to a spontaneously formed optical wavelength grating. We suggest that this grating arises from a self-organization or self-bunching of the atoms, an effect which is mediated by recoil just as in the free electron laser.
The interaction of an atomic gas confined inside a cavity with a strong electromagnetic field is numerically and theoretically investigated in a regime where recoil effects are not negligible. The spontaneous appearance of a density grating (atomic bunching) accompanied by the onset of coherent backpropagation is found to be ruled by a continuous phase-transition. Numerical tests allow us to convincingly prove that the transition is steered by the appearence of a periodic atomic density modulation. Consideration of different experimental relaxation mechanisms induces us to analyze the problem in nearly analytic form, in the large detuning limit, using both a Vlasov approach and a Fokker-Planck description. The application of our predictions to recent experimental findings, reported in [Phys. Rev. Lett. {\bf 91}, 183601 (2003)], yields a semi-quantitative agreement with the observations.
We present a review and extension of a recently made proposal [K. M. Gheri et al., Phys. Rev. Lett. 74, 678 (1995)] to utilize cold atoms in a Raman configuration as a uv-laser gain medium in the limit of the photon recoil shift exceeding the natural atomic linewidth and the Doppler broadening. A discussion of model assumptions is given as well as an analysis of the dependence of the gain on detunings and decay rates. Special emphasis is put on a calculation of the nonlinear gain that allows a self-consistent determination of the uv-laser intensity as a function of the model parameters. For a deep uv transition, the gain turns out to be of approximately the same order of magnitude as for comparable optical transitions including a significant enhancement through Raman coherences especially at weak laser intensities. Our calculations suggest the possibility of a cw deep uv laser, based on laser cooled metastable (e.g., helium) atoms.
We present a theoretical study of the interaction between light and a cold gasof three-level, ladder configuration atoms close to two-photon resonance. In particular, weinvestigate the existence of collective atomic recoil lasing (CARL) instabilities in differentregimes of internal atomic excitation and compare to previous studies of the CARL instabilityinvolving two-level atoms. In the case of two-level atoms, the CARL instability is quenchedat high pump rates with significant atomic excitation by saturation of the (one-photon)coherence, which produces the optical forces responsible for the instability and rapid heatingdue to high spontaneous emission rates. We show that in the two-photon CARL schemestudied here involving three-level atoms, CARL instabilities can survive at high pump rateswhen the atoms have significant excitation, due to the contributions to the optical forces frommultiple coherences and the reduction of spontaneous emission due to transitions betweenthe populated states being dipole forbidden. This two-photon CARL scheme may form thebasis of methods to increase the effective nonlinear optical response of cold atomic gases.
We present a microscopic laser model for many atoms coupled to a single-cavity mode, including the light forces, which result from atom-field momentum exchange. Within a semiclassical description, we solve the equations for the atomic motion and the internal dynamics to obtain analytic expressions for the optical potential and the friction force seen by each atom. When optical gain is maximum at frequencies where the light field extracts kinetic energy from the atomic motion, the dynamics combines optical lasing and motional cooling. From the corresponding momentum-diffusion coefficient we predict sub-Doppler temperatures in the stationary state. This generalizes the theory of cavity-enhanced laser cooling to active cavity systems. We identify the gain-induced reduction of the effective resonator linewidth as the key origin for the faster cooling and the lower temperatures, which implies that a bad cavity with a gain medium can replace a high-QQQ cavity. In addition, this shows the importance of light forces for gas lasers in the low-temperature limit, where atoms can arrange in a periodic pattern maximizing gain and counteracting spatial hole burning. Ultimately, in the low-temperature limit, such a setup should allow us to combine optical lasing and atom lasing in a single device.
We present an analysis of absorptive optical bistability in a system of cold atoms enclosed in a bidirectional ring cavity. This analysis is carried out using a system of equations that extends the so-called Maxwell-Bloch model to self-consistently include atomic center-of-mass motion. The analysis predicts an instability resulting in the simultaneous generation of an atomic density grating and a coherently backscattered radiation field. The formation of the density grating arises from a modulation of the radiation pressure forces exerted on the atoms. A consequence of this instability is that the lower transmission branch of the usual bistability curve, where atomic motion is neglected, can become unstable and the system switches to the upper transmission branch destroying the bistability.