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

Optical and Quantum Sensing and Precision Metrology II

Chirped pulse propagation influenced by coherent population trapping in molecular media

Yuri V. Rostovtsev, Colin Roy, Pooja Nadkarni Singh, Anil K. Patnaik

Published Mar 9, 2022• 0 citations
Publisher

Abstract

We study the excitation of the quantum coherence in a $\Lambda$-type molecular media and its influence on chirped pulse propagation. The coherent population trapping (CPT) of the ground states in the $\Lambda$-system results in fascinating new dynamics of pulse propagation through it. We have considered the two- and three-level molecules. The dressed state basis approach is employed, which provides deep physical insights showing interaction of “bright” and “dark” states with radiation. The level structure of the model is common for the molecular media, where the ground states maybe the ro-vibrational levels of the ground electronic state. We consider a gas of three-level atoms or molecules in the presence of two coherent optical pulses. We demonstrate the importance of role of the dark states. The presented results are important for applications to manipulation of quantum states for molecular detection in engineering, chemical, and biological applications.

DOI
10.1117/12.2617249

Related papers

Influence of coherent population trapping on Raman scattering

Pooja Nadkarni Singh, Anil K. Patnaik, Sukesh Roy +2 more

We have considered the Raman scattering in molecular media. Applying two laser fields in a two-photon resonance with vibrational transition, we have studied the role of rotational levels for excitation of vibrational coherence. It is shown that the molecular vibrational coherence strongly depends on the effect of coherent population trapping for rotational levels. The obtained results are important for applications of Raman spectroscopy to molecular detection in engineering, chemical, and biological applications.

Physical Review A•Aug 8, 2019•2 citations

Quantum Coherent Control and Propagation in Lambda System

Pooja Nadkarni Singh

Strong coherence in quasi-resonant laser driven system interferes with effective relaxations, resulting in behaviors like, coherent population trapping and Electromagnetically induced transparency. The Raman system can optimize this utilizing excited coherence in the lambda system when exposed to counter- intuitive pump-stokes pulses. The phenomenon can result in complete population transfer between vibrational levels called Stimulated Raman adiabatic passage(STIRAP). STIRAP and CHIRAP have been studied with Gaussian and chirped pulses. The optical propagation effects in dense medium for these phenomenon is studied to calculate the limitations and induced coherences. Further, the effect of rotational levels has been investigated. The molecular vibrational coherence strongly depends on the effect of rotational levels. The change in coherence interaction for ro-vibrational levels are reported and explained. We have considered the effects on the phase of radiation related to rotational mechanical motion of quantum system by taking advantages in ultra strong dispersion medium provided by quantum coherence in lambda system. The enhanced Fizeau effect on a single atom is observed.

•May 1, 2016•0 citations

Two-pulse propagation in a partially phase-coherent medium

B. D. Clader, Joseph H. Eberly

We analyze the effects of partial coherence of ground-state preparation on two-pulse propagation in a three-level $\ensuremath{\Lambda}$ medium, in contrast to previous treatments that have considered the cases of media whose ground states are characterized by probabilities (level populations) or by probability amplitudes (coherent pure states). We present analytic solutions of the Maxwell-Bloch equations, and we extend our analysis with numerical solutions to the same equations. We interpret these solutions in the bright and dark dressed-state basis, and show that they describe a population transfer between the bright and dark state. For mixed-state $\ensuremath{\Lambda}$ media with partial ground-state phase coherence the dark state can never be fully populated. This has implications for phase-coherent effects such as pulse matching, coherent population trapping, and electromagnetically induced transparency (EIT). We show that for partially phase-coherent three-level media, self-induced transparency dominates EIT and our results suggest a corresponding three-level area theorem.

arXiv:0807.4191•Physical Review A•Sep 5, 2008•15 citations

Effects of coherent population trapping in vibrational levels on group velocity and Raman scattering

Pooja Nadkarni Singh, Yuri V. Rostovtsev

We study Raman scattering in molecular media by applying two laser fields in a two-photon resonance with vibrational transition. The role of rotational levels has been investigated. It is shown that the molecular vibrational coherence strongly depends on the effect of coherent population trapping for rotational levels. The obtained results are important for application of Raman spectroscopy to molecular detection for engineering, chemical, and biological applications.

Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE•Mar 7, 2016•2 citations

Suppression of coherent scattering by coherent population trapping on molecular vibrational levels

Pooja Nadkarni Singh

Abstract Raman scattering has been studied in molecular media. The role of rotational levels has been investigated. It is shown that the molecular vibrational coherence strongly depends on the effect of coherent population trapping for rotational levels. The obtained results are important for application of Raman spectroscopy to molecular detection for engineering, chemical, and biological applications.

Coherent Phenomena•Jan 30, 2016•0 citations

Propagation of frequency-chirped laser pulses in a medium of atoms with a Λ -level scheme

G. Demeter, David Dzsotjan, Gagik P. Djotyan

We study the propagation of frequency-chirped laser pulses in optically thick media. We consider a medium of atoms with a $\ensuremath{\Lambda}$ level-scheme (Lambda atoms) and also, for comparison, a medium of two-level atoms. Frequency-chirped laser pulses that induce adiabatic population transfer between the atomic levels are considered. They induce transitions between the two lower (metastable) levels of the $\ensuremath{\Lambda}$-atoms and between the ground and excited states of the two-level atoms. We show that associated with this adiabatic population transfer in $\ensuremath{\Lambda}$-atoms, there is a regime of enhanced transparency of the medium---the pulses are distorted much less than in the medium of two-level atoms and retain their ability to transfer the atomic population much longer during propagation.

Physical Review A•Aug 30, 2007•8 citations
We study the excitation of the quantum coherence in a Λ\LambdaΛ-type molecular media and its influence on chirped pulse propagation. The coherent population trapping (CPT) of the ground states in the Λ\LambdaΛ-system results in fascinating new dynamics of pulse propagation through it. We have considered the two- and three-level molecules. The dressed state basis approach is employed, which provides deep physical insights showing interaction of “bright” and “dark” states with radiation. The level structure of the model is common for the molecular media, where the ground states maybe the ro-vibrational levels of the ground electronic state. We consider a gas of three-level atoms or molecules in the presence of two coherent optical pulses. We demonstrate the importance of role of the dark states. The presented results are important for applications to manipulation of quantum states for molecular detection in engineering, chemical, and biological applications.
We have considered the Raman scattering in molecular media. Applying two laser fields in a two-photon resonance with vibrational transition, we have studied the role of rotational levels for excitation of vibrational coherence. It is shown that the molecular vibrational coherence strongly depends on the effect of coherent population trapping for rotational levels. The obtained results are important for applications of Raman spectroscopy to molecular detection in engineering, chemical, and biological applications.
Strong coherence in quasi-resonant laser driven system interferes with effective relaxations, resulting in behaviors like, coherent population trapping and Electromagnetically induced transparency. The Raman system can optimize this utilizing excited coherence in the lambda system when exposed to counter- intuitive pump-stokes pulses. The phenomenon can result in complete population transfer between vibrational levels called Stimulated Raman adiabatic passage(STIRAP). STIRAP and CHIRAP have been studied with Gaussian and chirped pulses. The optical propagation effects in dense medium for these phenomenon is studied to calculate the limitations and induced coherences. Further, the effect of rotational levels has been investigated. The molecular vibrational coherence strongly depends on the effect of rotational levels. The change in coherence interaction for ro-vibrational levels are reported and explained. We have considered the effects on the phase of radiation related to rotational mechanical motion of quantum system by taking advantages in ultra strong dispersion medium provided by quantum coherence in lambda system. The enhanced Fizeau effect on a single atom is observed.
We analyze the effects of partial coherence of ground-state preparation on two-pulse propagation in a three-level $\ensuremath{\Lambda}$ medium, in contrast to previous treatments that have considered the cases of media whose ground states are characterized by probabilities (level populations) or by probability amplitudes (coherent pure states). We present analytic solutions of the Maxwell-Bloch equations, and we extend our analysis with numerical solutions to the same equations. We interpret these solutions in the bright and dark dressed-state basis, and show that they describe a population transfer between the bright and dark state. For mixed-state $\ensuremath{\Lambda}$ media with partial ground-state phase coherence the dark state can never be fully populated. This has implications for phase-coherent effects such as pulse matching, coherent population trapping, and electromagnetically induced transparency (EIT). We show that for partially phase-coherent three-level media, self-induced transparency dominates EIT and our results suggest a corresponding three-level area theorem.
We study the propagation of frequency-chirped laser pulses in optically thick media. We consider a medium of atoms with a $\ensuremath{\Lambda}$ level-scheme (Lambda atoms) and also, for comparison, a medium of two-level atoms. Frequency-chirped laser pulses that induce adiabatic population transfer between the atomic levels are considered. They induce transitions between the two lower (metastable) levels of the $\ensuremath{\Lambda}$-atoms and between the ground and excited states of the two-level atoms. We show that associated with this adiabatic population transfer in $\ensuremath{\Lambda}$-atoms, there is a regime of enhanced transparency of the medium---the pulses are distorted much less than in the medium of two-level atoms and retain their ability to transfer the atomic population much longer during propagation.