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

International Conference on Ultrafast Phenomena

Coherent Control of the Selected Excited State by Two-Color Multipulse Excitation

Kenta Abe, R. Nakamura, Hideki Hashimoto, M. Yoshizawa

Published Jan 1, 2010• 0 citations
Publisher

Abstract

The selected excited state is controlled by combination of the first pump pulse generating the target state and the second shaped pump pulse. Coherent vibrations can be induced even in the optically forbidden state.
DOI
10.1364/up.2010.me51

Related papers

Coherent control of population transfer of the excited double states based on pulse shaping

Zhenhao Wang, Yanghua Zhang, Quanjun Wang +2 more

Laser Technology•Jan 1, 2016•0 citations

Control of excited-state population and vibrational coherence with shaped-resonant and near-resonant excitation

Tiago Buckup, Jürgen Hauer, Carles Serrat +1 more

We investigated numerically and experimentally the enhancement of vibrational coherence and population transfer in solution using tailored pulses. The general control mechanism is based on the precise control of the absorption after excitation with multipulses. Transient absorption was used as an experimental method to quantify the enhancement after the excitation with a shaped pump pulse in the low-pulse energy regime. A density-matrix approach was used to investigate the effect of the shaped excitation of a four-level system (two ground-state vibrational levels + two excited-state vibrational levels). Density-matrix simulation results suggest similar wavelength dependence as observed in the transient absorption experiment. The results show that enhancement of population transfer and vibrational coherence depends crucially on the overlap between the excitation pulse spectrum and the molecular absorption band.

Journal of Physics B Atomic Molecular and Optical Physics•Mar 26, 2008•34 citations

Coherent control of nonresonant two-photon excitation in molecules

Jing Su, Shaohao Chen, Agnieszka Jaroń-Becker +1 more

Bulletin of the American Physical Society•Jun 15, 2011•0 citations

Parametric polarization pulse shaping methods and control of excitation dynamics in ultracold rubidium

Fabian Weise

This work focuses on the developments of ultrafast laser pulse shaping techniques and their application to diatomic molecular systems in order to reveal fundamental effects in light matter interaction. It describes the development of a new pulse shaper consisting of a sequence of four liquid crystal arrays and a polarizer. This pulse shaper is the first non- interferometric setup for unrestricted phase, amplitude, and polarization shaping. Moreover, a parametric encoding of the electrical field was developed which allowed for generating pulse sequences consisting of several sub-pulses. Each sub-pulse can be controlled in its physically apparent parameters: energy, position in time, phase, and chirps as well as state of polarization with ellipticity, orientation, and helicity. The feasibility of the setup is illustrated by systematic variations of single and double pulses, which are experimentally generated and measured. In these series of pulses, one of the pulses parameters is varied while the other parameters are kept constant. This proves the precise control of the pulse shape. Further, more complex pulses are shown to give an impression of the capabilities of this setup in combination with the parameterization. For some fields of application, it could be desirable to guide the phase, amplitude and polarization shaped pulses through an optical fiber. For example, life science could benefit from shaped pulses in the area of imaging and photodynamic therapy. In order to make the shaped pulses available at the distal end of an optical fiber, the effects of the fiber have to be compensated. In this work, the generation of phase, amplitude, and polarization shaped pulses after transmission trough an optical fiber is presented. This is demonstrated for two types of optical fibers – a standard single-mode fiber and a microstructured hollow core photonic crystal fiber. The procedure for the determined generation of parametrically shaped pulses differs for both types of optical fibers. The capabilities of parametrically shaped pulse sequences are – again – illustrated by a series of example pulses. The parametrically shaped pulses transmitted through the hollow core fiber are implemented in a coherent control experiment. For this purpose, the potassium dimer produced in a molecular beam serves as a test system. The multi-photon ionization is studied by a closed feedback loop optimization and shaper-assisted pump-probe spectroscopy. These experiments revealed the excitation path including the vibrational dynamics in the first and second excited state. Further, the relevance of the polarization control in the excitation process is highlighted. Moreover, coherent control techniques are applied to investigate the interaction of shaped femtosecond laser pulses with ultracold atoms and molecules. The focus of these experiments is the control of the photoassociation of a colliding atom pair to a bound molecule. This process is investigated using two-color pump-probe spectroscopy. The molecular transients are compared to theoretical calculations. The analysis of this data reveals the interaction process which is discussed in the time and frequency domain. In a second experiment, the multi-photon ionization of ultracold rubidium dimers is optimized in a closed feedback loop. In this optimization, a parameterization in the frequency domain is employed which extracts the relevant transition frequencies. In combination with a complementary experiment the excitation pathway was revealed.

•Jan 1, 2010•0 citations

Coherent Control Experiments on Molecular Multiphoton Excitation

A.F. Linskens, Nico J. Dam, J. Reuß

Abstracts of papers - American Chemical Society•Jan 1, 1995•0 citations

Experimental and numerical investigation of a phase-only control mechanism in the linear intensity regime

Elisabeth Brühl, Tiago Buckup, Marcus Motzkus

Mechanisms and optimal experimental conditions in coherent control still intensely stimulate debates. In this work, a phase-only control mechanism in an open quantum system is investigated experimentally and numerically. Several parameterizations for femtosecond pulse shaping (combination of chirp and multipulses) are exploited in transient absorption of a prototype organic molecule to control population and vibrational coherence in ground and excited states. Experimental results are further numerically simulated and corroborated with a four-level density-matrix model, which reveals a phase-only control mechanism based on the interaction between the tailored phase of the excitation pulse and the induced transient absorption. In spite of performing experiment and numerical simulations in the linear regime of excitation, the control effect amplitude depends non-linearly on the excitation energy and is explained as a pump-dump control mechanism. No evidence of single-photon control is observed with the model. Moreover, our results also show that the control effect on the population and vibrational coherence is highly dependent on the spectral detuning of the excitation spectrum. Contrary to the popular belief in coherent control experiments, spectrally resonant tailored excitation will lead to the control of the excited state only for very specific conditions.

The Journal of Chemical Physics•Jun 7, 2018•8 citations
We investigated numerically and experimentally the enhancement of vibrational coherence and population transfer in solution using tailored pulses. The general control mechanism is based on the precise control of the absorption after excitation with multipulses. Transient absorption was used as an experimental method to quantify the enhancement after the excitation with a shaped pump pulse in the low-pulse energy regime. A density-matrix approach was used to investigate the effect of the shaped excitation of a four-level system (two ground-state vibrational levels + two excited-state vibrational levels). Density-matrix simulation results suggest similar wavelength dependence as observed in the transient absorption experiment. The results show that enhancement of population transfer and vibrational coherence depends crucially on the overlap between the excitation pulse spectrum and the molecular absorption band.
This work focuses on the developments of ultrafast laser pulse shaping techniques and their application to diatomic molecular systems in order to reveal fundamental effects in light matter interaction. It describes the development of a new pulse shaper consisting of a sequence of four liquid crystal arrays and a polarizer. This pulse shaper is the first non- interferometric setup for unrestricted phase, amplitude, and polarization shaping. Moreover, a parametric encoding of the electrical field was developed which allowed for generating pulse sequences consisting of several sub-pulses. Each sub-pulse can be controlled in its physically apparent parameters: energy, position in time, phase, and chirps as well as state of polarization with ellipticity, orientation, and helicity. The feasibility of the setup is illustrated by systematic variations of single and double pulses, which are experimentally generated and measured. In these series of pulses, one of the pulses parameters is varied while the other parameters are kept constant. This proves the precise control of the pulse shape. Further, more complex pulses are shown to give an impression of the capabilities of this setup in combination with the parameterization. For some fields of application, it could be desirable to guide the phase, amplitude and polarization shaped pulses through an optical fiber. For example, life science could benefit from shaped pulses in the area of imaging and photodynamic therapy. In order to make the shaped pulses available at the distal end of an optical fiber, the effects of the fiber have to be compensated. In this work, the generation of phase, amplitude, and polarization shaped pulses after transmission trough an optical fiber is presented. This is demonstrated for two types of optical fibers – a standard single-mode fiber and a microstructured hollow core photonic crystal fiber. The procedure for the determined generation of parametrically shaped pulses differs for both types of optical fibers. The capabilities of parametrically shaped pulse sequences are – again – illustrated by a series of example pulses. The parametrically shaped pulses transmitted through the hollow core fiber are implemented in a coherent control experiment. For this purpose, the potassium dimer produced in a molecular beam serves as a test system. The multi-photon ionization is studied by a closed feedback loop optimization and shaper-assisted pump-probe spectroscopy. These experiments revealed the excitation path including the vibrational dynamics in the first and second excited state. Further, the relevance of the polarization control in the excitation process is highlighted. Moreover, coherent control techniques are applied to investigate the interaction of shaped femtosecond laser pulses with ultracold atoms and molecules. The focus of these experiments is the control of the photoassociation of a colliding atom pair to a bound molecule. This process is investigated using two-color pump-probe spectroscopy. The molecular transients are compared to theoretical calculations. The analysis of this data reveals the interaction process which is discussed in the time and frequency domain. In a second experiment, the multi-photon ionization of ultracold rubidium dimers is optimized in a closed feedback loop. In this optimization, a parameterization in the frequency domain is employed which extracts the relevant transition frequencies. In combination with a complementary experiment the excitation pathway was revealed.
Mechanisms and optimal experimental conditions in coherent control still intensely stimulate debates. In this work, a phase-only control mechanism in an open quantum system is investigated experimentally and numerically. Several parameterizations for femtosecond pulse shaping (combination of chirp and multipulses) are exploited in transient absorption of a prototype organic molecule to control population and vibrational coherence in ground and excited states. Experimental results are further numerically simulated and corroborated with a four-level density-matrix model, which reveals a phase-only control mechanism based on the interaction between the tailored phase of the excitation pulse and the induced transient absorption. In spite of performing experiment and numerical simulations in the linear regime of excitation, the control effect amplitude depends non-linearly on the excitation energy and is explained as a pump-dump control mechanism. No evidence of single-photon control is observed with the model. Moreover, our results also show that the control effect on the population and vibrational coherence is highly dependent on the spectral detuning of the excitation spectrum. Contrary to the popular belief in coherent control experiments, spectrally resonant tailored excitation will lead to the control of the excited state only for very specific conditions.