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

Physical Review A

Nonlinear theory of lasers without inversion with two upper lasing levels

Shi Yao Zhu, Ernst E. Fill

Published Nov 1, 1990• 34 citations
Publisher

Abstract

The nonlinear equation of motion for the laser field is obtained by using a perturbation method up to third order. The linear gain and intensity of the laser field are obtained. A perfect lasing without inversion can be achieved when ${\mathrm{\ensuremath{\delta}}}_{3}$${\mathrm{\ensuremath{\mu}}}_{2}$ \ensuremath{\surd}${\mathrm{\ensuremath{\Gamma}}}_{2}$ =-${\mathrm{\ensuremath{\delta}}}_{2}$${\mathrm{\ensuremath{\mu}}}_{3}$ \ensuremath{\surd}${\mathrm{\ensuremath{\Gamma}}}_{3}$ .

DOI
10.1103/physreva.42.5684

Related papers

Nonlinear theory of noninversion lasers of an open three-level system

Shi-Yao Zhu, De-Zhong Wang, Jin-Yue Gao

A nonlinear theory of a noninversion laser of an open three-level system based on electromagnetically induced transparency is given. In this noninversion laser model, a nonselective pumping mechanism is used for obtaining lasing gain such that the population in the lower lasing level is always larger than a half of the total population no matter whether the driving field is on or off. In the lasing region, there is no direct pumping to the upper level. The conditions for the existence of a nontrivial and stable laser field are obtained. The dependence of the laser intensity on the intensity of the driving field and the ratio of the two decay rates from the upper level has been obtained, and the ways to obtain a large laser field have been studied.

Physical Review A•Feb 1, 1997•28 citations

The Nonlinear Theory of Lasing Without Inversion in an Open Simple Three level Atomic System

Fan Xi

WT5”BZ]:In this paper we gave the nonlinear theory of lasing without inversion in an open simple three level atomic system.We studied the effects of the Rabi frequencies of the probe and the driving fields,the injection rates,the exit rate,as well as the decay rates between atomic levels on the gain without inversion,the population difference and the coherence term of the system,and discussed the stability of the gain without inversion. [WT5”HZ]

Journal of Optoelectronics·laser•Jan 1, 2000•0 citations

Nonlinear dynamics in a single mode three-level laser without inversion

A. G. Vladimirov, Paul Mandel, Susanne F. Yelin +2 more

We characterize analytically the nature of the lasing solutions of a laser operating without population inversion. We consider models involving three-level media interacting with a strong driving field and a lasing field in the vicinity of the lasing threshold. We assess the influence of different relaxation and pumping schemes on the dynamics of these lasers. We use the atom-field detuning, the cavity detuning, and the linear gain as bifurcation parameters. Depending on their values, the stable lasing solution is shown to be cw or self-pulsing. We show that the optimal lasing operation is achieved if both the driving field frequency and the cavity frequency are out of resonance with the atomic frequencies. Physically, the lasing regimes arise from nonlinearly interacting sidebands induced in the lasing medium by atomic interference.

Physical review. E, Statistical physics, plasmas, fluids, and related interdisciplinary topics•Feb 1, 1998•9 citations

Comment on ‘‘Theory of lasers without inversion’’

Shi-Yao Zhu, James D. Cresser, H. Fearn

We prove that lasing without inversion is impossible in the three-level system with two active upper levels that are mixed by applied low-frequency electromagnetic radiation. Such lasing was recently proposed by Blok and Krochik [Phys. Rev. A 41, 1517 (1990)].

Physical Review A•May 1, 1991•2 citations

Lasing without inversion—gain enhancement with a colored pump

Gautam Vemuri, G. S. Agarwal, THOMAS W. MOSSBERG

Most models of lasing without inversion utilize incoherent pumping of the upper state of the transition on which lasing occurs. We suggest replacing incoherent pumping by a color pump (i.e. laser with a finite bandwidth) for selective pumping of the upper state, where one can also take advantage of the tunability of the laser. A three-level ladder system is considered with the upper two levels providing the lasing transition. We reduce the density matrix equations for this system to a set of eight coupled Langevin equations with multiplicative noise. These equations are solved using Monte-Carlo methods to obtain the gain as a function of various atom and field parameters. The use of the color pump leads to a significant enhancement in gain. Using a dressed states formalism, an explanation of the possible physical mechanism behind this gain enhancement is provided.

Annual Meeting Optical Society of America•Jan 1, 1993•0 citations

Lasing without inversion: Theory of transient behavior

Victor R. Blok, Gennady M. Krochik

We present consistent transient theory of lasing without inversion and show by numerical analysis that pulse-mode lasing is feasible in a two-level system with split upper levels coupled by an external high-frequency electromagnetic field.

Physical Review A•Aug 1, 1991•20 citations
The nonlinear equation of motion for the laser field is obtained by using a perturbation method up to third order. The linear gain and intensity of the laser field are obtained. A perfect lasing without inversion can be achieved when {\mathrm{\ensuremath{\delta}}}_{3}$${\mathrm{\ensuremath{\mu}}}_{2} \ensuremath{\surd}\ensuremathΓ2{\mathrm{\ensuremath{\Gamma}}}_{2}\ensuremathΓ2​ =-{\mathrm{\ensuremath{\delta}}}_{2}$${\mathrm{\ensuremath{\mu}}}_{3} \ensuremath{\surd}\ensuremathΓ3{\mathrm{\ensuremath{\Gamma}}}_{3}\ensuremathΓ3​ .
A nonlinear theory of a noninversion laser of an open three-level system based on electromagnetically induced transparency is given. In this noninversion laser model, a nonselective pumping mechanism is used for obtaining lasing gain such that the population in the lower lasing level is always larger than a half of the total population no matter whether the driving field is on or off. In the lasing region, there is no direct pumping to the upper level. The conditions for the existence of a nontrivial and stable laser field are obtained. The dependence of the laser intensity on the intensity of the driving field and the ratio of the two decay rates from the upper level has been obtained, and the ways to obtain a large laser field have been studied.
We characterize analytically the nature of the lasing solutions of a laser operating without population inversion. We consider models involving three-level media interacting with a strong driving field and a lasing field in the vicinity of the lasing threshold. We assess the influence of different relaxation and pumping schemes on the dynamics of these lasers. We use the atom-field detuning, the cavity detuning, and the linear gain as bifurcation parameters. Depending on their values, the stable lasing solution is shown to be cw or self-pulsing. We show that the optimal lasing operation is achieved if both the driving field frequency and the cavity frequency are out of resonance with the atomic frequencies. Physically, the lasing regimes arise from nonlinearly interacting sidebands induced in the lasing medium by atomic interference.
Most models of lasing without inversion utilize incoherent pumping of the upper state of the transition on which lasing occurs. We suggest replacing incoherent pumping by a color pump (i.e. laser with a finite bandwidth) for selective pumping of the upper state, where one can also take advantage of the tunability of the laser. A three-level ladder system is considered with the upper two levels providing the lasing transition. We reduce the density matrix equations for this system to a set of eight coupled Langevin equations with multiplicative noise. These equations are solved using Monte-Carlo methods to obtain the gain as a function of various atom and field parameters. The use of the color pump leads to a significant enhancement in gain. Using a dressed states formalism, an explanation of the possible physical mechanism behind this gain enhancement is provided.