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

Journal of Modern Optics

Optimal coherence via chirped pulse adiabatic passage in the presence of dephasing

Svetlana Malinovskaya, Vladimir S. Malinovsky

Published Nov 10, 2008• 4 citations
Publisher

Abstract

We propose the adiabatic passage control scheme to maximize coherence in a predetermined molecular vibrational mode via two-photon Raman transitions. We investigate vibrational energy relaxation and collisional dephasing as factors of coherence loss, and demonstrate the possibility for sustaining high value of coherence in the presence of dephasing by two chirped pulse trains. The proposed method may be used to advance imaging techniques currently applied in the coherent anti-stokes Raman scattering (CARS) microscopy.

DOI
10.1080/09500340802267142

Related papers

Optimal Coherence Using Chirped Pulse Trains for Enhanced Imaging

Svetlana Malinovskaya

We propose adiabatic passage control scheme to maximize coherence in selected vibrational mode. We demonstrate possibility for sustaining high coherence in the presence of dephasing by two chirped pulse trains. Method may enhance CARS imaging.

OSA Optics and Photonics Congress: Advances in Imaging•Jan 1, 2009•0 citations

Robust control by two chirped pulse trains in the presence of decoherence

Svetlana Malinovskaya

We discuss a novel method to create maximum coherence in a two-level system that is selectively excited among many having similar frequencies by making use of two specifically chirped pulses in the Raman configuration. The feasibility of the method is analyzed in the presence of decoherence caused by vibrational energy relaxation and collisional dephasing. It has been demonstrated that a high value of coherence may be sustained by the implementation of two chirped pulse trains prepared in accordance with the proposed method and having the same period as the vibrational energy relaxation time. Maximum coherence between predetermined states in atoms and molecules is an important aspect of many problems in quantum optics. One possible example is the generation of optimal CARS signal in the CARS microscopy aiming to reveal structures constituted of particular molecular groups. Presently, in experiments on biological imaging, the CARS signal is generated with implementation of picosecond laser pulses (1), a narrow spectral bandwidth of which allows one to address a particular molecular group with a good accuracy. Aiming to improve chemical sensitivity and to get optimal CARS signal for given pulse intensity we propose to use the quantum control methods for selective excitation of required vibrations in complex molecular systems. We developed a novel method that allows one to achieve maximum coherence in a predetermined vibrational mode in a multimode mole- cular system via the Raman transitions induced by the pump and Stokes chirped pulses. According to the Maxwell-Bloch equations, maximum coherence is the condition for the CARS signal to acquire the highest intensity upon propagation through a molecular medium (2). The mechanism of creation of maximum coherence underlying the proposed method is based on the adiabatic passage. An important aspect in the investigations asso- ciated with a condense phase is decoherence. Two main sources of decoherence, the vibrational energy relaxa- tion and collisional dephasing, may significantly affect the CARS signal intensity. The phase control of molecular processes in the presence of collisions was

Bulletin of the American Physical Society•May 30, 2008•0 citations

Optimal Coherence Using Chirped Pulse Trains for Enhanced Imaging

Svetlana Malinovskaya

We propose adiabatic passage control scheme to maximize coherence in selected vibrational mode. We demonstrate possibility for sustaining high coherence in the presence of dephasing by two chirped pulse trains. Method may enhance CARS imaging.

Frontiers in Optics•Jan 1, 2008•0 citations

Prevention of decoherence by two femtosecond chirped pulse trains

Svetlana Malinovskaya

We study the vibrational energy relaxation (VER) and collisional dephasing as channels of coherence loss in a vibrational mode that is selectively excited using chirped pulse adiabatic passage in the Raman configuration. Based on the dressed state picture analysis we propose a method to reduce decoherence using femtosecond chirped pulse trains. When applied with a period close to the VER time, the pulse trains allow one to sustain high coherence in the selected vibrational mode.

Optics Letters•Sep 26, 2008•25 citations

Effects of phase and coupling between the vibrational modes on selective excitation in coherent anti-Stokes Raman scattering microscopy

Vishesha Patel, Vladimir S. Malinovsky, Svetlana Malinovskaya

Coherent anti-Stokes Raman scattering (CARS) microscopy has been a major tool of investigation of biological structures as it contains the vibrational signature of molecules. A quantum control method based on chirped pulse adiabatic passage was recently proposed for selective excitation of a predetermined vibrational mode in CARS microscopy [Malinovskaya and Malinovsky, Opt. Lett. 32, 707 (2007)]. The method utilizes the chirp sign variation at the peak pulse amplitude and gives a robust adiabatic excitation of the desired vibrational mode. Using this method, we investigate the impact of coupling between vibrational modes in molecules on controllability of excitation of the CARS signal. We analyze two models of two coupled two-level systems (TLSs) having slightly different transitional frequencies. The first model, featuring degenerate ground states of the TLSs, gives robust adiabatic excitation and maximum coherence in the resonant TLS for positive value of the chirp. In the second model, implying nondegenerate ground states in the TLSs, a population distribution is observed in both TLSs, resulting in a lack of selectivity of excitation and low coherence. It is shown that the relative phase and coupling between the TLSs play an important role in optimizing coherence in the desired vibrational mode and suppressing unwanted transitions in CARS microscopy.

Physical Review A•Jun 8, 2010•13 citations

Chirped Pulse Control of Raman Coherence in Atoms and Molecules

Jabir Chathanathil, Svetlana Malinovskaya

A novel chirped pulse control scheme is presented based on Coherent Anti-Stokes Raman Spectroscopy (C-CARS) aiming at maximizing the vibrational coherence in atoms and molecules. The scheme utilizes chirping of the three incoming pulses, the pump, the Stokes and the probe, in the four-wave mixing process of C-CARS to fulfill the adiabatic passage conditions. The derivation of the scheme is based on simplifying the four-level system into a 'super-effective' two level system via rotating wave approximation and adiabatic elimination of the excited state manifold. The robustness, spectral selectivity and adiabatic nature of C-CARS method may prove useful for sensing, imaging, and detection. It is demonstrated that the selectivity in excitation of vibrational degrees of freedom can be controlled by carefully choosing the spectral chirp rate of the pulses. The C-CARS control scheme is applied to a surrogate methanol molecule to generate an optimal anti-Stokes signal backscattered from a cloud of molecules a kilometer away. The theory is based on the solution of the coupled Maxwell-Liouville von Neumann equations and focuses on the quantum effects induced in the target molecules by the control pulse trains. The propagation effects of pulses through the medium are evaluated and the buildup of the molecular-specific anti-Stokes signal is demonstrated numerically. A deep learning technique, using Convolutional Neural Networks (CNN), is implemented to characterize the control pulses and evaluate time-dependent phase characteristics from them. The effects of decoherence induced by spontaneous decay and collisional dephasing are also examined. Additionally, we present the technique of Fractional Stimulated Raman Adiabatic Passage (F-STIRAP) and demonstrate that it can be utilized for remote detection in a multi-level system by creation of a maximally coherent superposition state.

arXiv:2309.01232•Sep 3, 2023•0 citations
We propose the adiabatic passage control scheme to maximize coherence in a predetermined molecular vibrational mode via two-photon Raman transitions. We investigate vibrational energy relaxation and collisional dephasing as factors of coherence loss, and demonstrate the possibility for sustaining high value of coherence in the presence of dephasing by two chirped pulse trains. The proposed method may be used to advance imaging techniques currently applied in the coherent anti-stokes Raman scattering (CARS) microscopy.
We discuss a novel method to create maximum coherence in a two-level system that is selectively excited among many having similar frequencies by making use of two specifically chirped pulses in the Raman configuration. The feasibility of the method is analyzed in the presence of decoherence caused by vibrational energy relaxation and collisional dephasing. It has been demonstrated that a high value of coherence may be sustained by the implementation of two chirped pulse trains prepared in accordance with the proposed method and having the same period as the vibrational energy relaxation time. Maximum coherence between predetermined states in atoms and molecules is an important aspect of many problems in quantum optics. One possible example is the generation of optimal CARS signal in the CARS microscopy aiming to reveal structures constituted of particular molecular groups. Presently, in experiments on biological imaging, the CARS signal is generated with implementation of picosecond laser pulses (1), a narrow spectral bandwidth of which allows one to address a particular molecular group with a good accuracy. Aiming to improve chemical sensitivity and to get optimal CARS signal for given pulse intensity we propose to use the quantum control methods for selective excitation of required vibrations in complex molecular systems. We developed a novel method that allows one to achieve maximum coherence in a predetermined vibrational mode in a multimode mole- cular system via the Raman transitions induced by the pump and Stokes chirped pulses. According to the Maxwell-Bloch equations, maximum coherence is the condition for the CARS signal to acquire the highest intensity upon propagation through a molecular medium (2). The mechanism of creation of maximum coherence underlying the proposed method is based on the adiabatic passage. An important aspect in the investigations asso- ciated with a condense phase is decoherence. Two main sources of decoherence, the vibrational energy relaxa- tion and collisional dephasing, may significantly affect the CARS signal intensity. The phase control of molecular processes in the presence of collisions was
Coherent anti-Stokes Raman scattering (CARS) microscopy has been a major tool of investigation of biological structures as it contains the vibrational signature of molecules. A quantum control method based on chirped pulse adiabatic passage was recently proposed for selective excitation of a predetermined vibrational mode in CARS microscopy [Malinovskaya and Malinovsky, Opt. Lett. 32, 707 (2007)]. The method utilizes the chirp sign variation at the peak pulse amplitude and gives a robust adiabatic excitation of the desired vibrational mode. Using this method, we investigate the impact of coupling between vibrational modes in molecules on controllability of excitation of the CARS signal. We analyze two models of two coupled two-level systems (TLSs) having slightly different transitional frequencies. The first model, featuring degenerate ground states of the TLSs, gives robust adiabatic excitation and maximum coherence in the resonant TLS for positive value of the chirp. In the second model, implying nondegenerate ground states in the TLSs, a population distribution is observed in both TLSs, resulting in a lack of selectivity of excitation and low coherence. It is shown that the relative phase and coupling between the TLSs play an important role in optimizing coherence in the desired vibrational mode and suppressing unwanted transitions in CARS microscopy.
A novel chirped pulse control scheme is presented based on Coherent Anti-Stokes Raman Spectroscopy (C-CARS) aiming at maximizing the vibrational coherence in atoms and molecules. The scheme utilizes chirping of the three incoming pulses, the pump, the Stokes and the probe, in the four-wave mixing process of C-CARS to fulfill the adiabatic passage conditions. The derivation of the scheme is based on simplifying the four-level system into a 'super-effective' two level system via rotating wave approximation and adiabatic elimination of the excited state manifold. The robustness, spectral selectivity and adiabatic nature of C-CARS method may prove useful for sensing, imaging, and detection. It is demonstrated that the selectivity in excitation of vibrational degrees of freedom can be controlled by carefully choosing the spectral chirp rate of the pulses. The C-CARS control scheme is applied to a surrogate methanol molecule to generate an optimal anti-Stokes signal backscattered from a cloud of molecules a kilometer away. The theory is based on the solution of the coupled Maxwell-Liouville von Neumann equations and focuses on the quantum effects induced in the target molecules by the control pulse trains. The propagation effects of pulses through the medium are evaluated and the buildup of the molecular-specific anti-Stokes signal is demonstrated numerically. A deep learning technique, using Convolutional Neural Networks (CNN), is implemented to characterize the control pulses and evaluate time-dependent phase characteristics from them. The effects of decoherence induced by spontaneous decay and collisional dephasing are also examined. Additionally, we present the technique of Fractional Stimulated Raman Adiabatic Passage (F-STIRAP) and demonstrate that it can be utilized for remote detection in a multi-level system by creation of a maximally coherent superposition state.