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

Quantum Electronics and Laser Science Conference

Light Amplification without Population Inversion by using Laser-Cooled Rubidium Atoms

Noritsugu Sbiokawa, Yoshio Torii, Takuya Hirano, Takahiro Kuga

Published May 18, 1997• 3 citations
OpenAlex

Abstract

Complete transparency via effect of quantum interference in a A-type three-level atomic system was observed by using laser-cooled rubidium atoms. We also demonstrated inversionless amplification of weak probe laser in this system.

Related papers

Light amplification without population inversion by using laser-cooled rubidium atoms

Noritsugu Shiokawa, Yoshio Toril, Takuya Hirano +1 more

Optics and Photonics News•Oct 1, 1997•0 citations

Inversionless amplification in the three-level atoms with and without a hidden inversion in reservoir

Olga A. Kocharovskaya, Yuri V. Rostovtsev, Ataç İmamoğlu

We consider the problem of amplification without inversion in a three-level atomic system. When atoms are driven by a field reservoir and a low-frequency coherent field, amplification of a high-frequency probe field may occur even when there is no population inversion on any atomic transition. We prove that, depending on the ratio of the probe and coherent drive field frequencies, which we term the frequency up-conversion factor, this process may or may not require hidden inversion in the field reservoir. In the special case of a frequency up-conversion factor less than 2, we demonstrate that amplification is possible even if the field reservoir is in complete thermal equilibrium: this represents a new kind of coherent radiation source, distinct from both conventional lasers and lasers without inversion.

Physical Review A•Jul 1, 1998•26 citations

Normal or anomalous dispersion and gain in a resonant coherent medium

Hoonsoo Kang, Lingling Wen, Yifu Zhu

We show that in a four-level atomic system with electromagnetically induced transparency, a coherent pump field can induce light amplification without or with population inversion. As the pump field intensity increases, the atomic system evolves from normal dispersion and amplification without population inversion into anomalous dispersion and amplification with population inversion. We report an experiment on light amplification in cold rubidium atoms and present experimental measurements that agree with theoretical calculations based on the four-level model system.

APS•May 1, 2003•0 citations

Normal or anomalous dispersion and gain in a resonant coherent medium

Hoonsoo Kang, Lingling Wen, Yifu Zhu

We show that in a four-level atomic system with electromagnetically induced transparency, a coherent pump field can induce light amplification without or with population inversion. As the pump field intensity increases, the atomic system evolves from normal dispersion and amplification without population inversion into anomalous dispersion and amplification with population inversion. We report an experiment on light amplification in cold rubidium atoms and present experimental measurements that agree with theoretical calculations based on the four-level model system.

Physical Review A•Dec 5, 2003•79 citations

Amplification without population inversion

Olga A. Kocharovskaya, Paul Mandel, Yakov I. Khanin

Three- and four-level schemes of inversionless amplification with different types of coherent pumping is reviewed. Amplification without inversion between the 'bare' states is a result of population inversion between eigenstates of the density matrix. In particular, it can be achieved due to the coherent population trapping, i.e., effective removal from the interaction with the field a fraction of atoms at lower levels.

Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE•Dec 16, 1992•2 citations

Light amplification and squeezing in coherently pumped atomic systems

Yifu Zhu, Min Xiao

Light amplification without population inversion may be induced by optical coherence among the coupled slates driven by laser fields or by the difference between the absorption and emission paths manifested by quantum interference. The optical coherence and quantum interference may lead to interesting statistical properties, such as narrower intrinsic linewidths and amplitude squeezing in inversionless lasers with coherently pumped atomic systems as active media.

•May 8, 1994•0 citations
We consider the problem of amplification without inversion in a three-level atomic system. When atoms are driven by a field reservoir and a low-frequency coherent field, amplification of a high-frequency probe field may occur even when there is no population inversion on any atomic transition. We prove that, depending on the ratio of the probe and coherent drive field frequencies, which we term the frequency up-conversion factor, this process may or may not require hidden inversion in the field reservoir. In the special case of a frequency up-conversion factor less than 2, we demonstrate that amplification is possible even if the field reservoir is in complete thermal equilibrium: this represents a new kind of coherent radiation source, distinct from both conventional lasers and lasers without inversion.
We show that in a four-level atomic system with electromagnetically induced transparency, a coherent pump field can induce light amplification without or with population inversion. As the pump field intensity increases, the atomic system evolves from normal dispersion and amplification without population inversion into anomalous dispersion and amplification with population inversion. We report an experiment on light amplification in cold rubidium atoms and present experimental measurements that agree with theoretical calculations based on the four-level model system.
We show that in a four-level atomic system with electromagnetically induced transparency, a coherent pump field can induce light amplification without or with population inversion. As the pump field intensity increases, the atomic system evolves from normal dispersion and amplification without population inversion into anomalous dispersion and amplification with population inversion. We report an experiment on light amplification in cold rubidium atoms and present experimental measurements that agree with theoretical calculations based on the four-level model system.