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

Effects of pulses with simple phase and frequency modulations

Debabrata Goswami, Warren S. Warren

Published Dec 1, 1994• 19 citations
Publisher

Abstract

The effects of pulse shapes with simple phase and frequency modulation (phase proportional to amplitude or intensity, frequency proportional to intensity) are explored numerically. Many such shapes can be generated by combining self-phase-modulation with modern laser pulse-shaping capabilities (which are more flexible for amplitude modulation than for frequency modulation). Even though all of these wave forms begin and end at the same frequency (and hence violate the mathematical conditions for adiabatic inversion), we show that they can generate adiabatic population inversion or suppress intramolecular energy redistribution.

DOI
10.1103/physreva.50.5190

Related papers

Dynamics of Atomic Excitations by Chirped Pulses

C. E. Carroll, F. T. Hioe

We have found new analytic results for a wide variety of atomic excitation processes which involve the use of amplitude-and frequency-modulated laser pulses: (1) We have unified all the previously known solutions including those of Rosen and Zener,1 Landau2 and Zener,3 Rabi,4 Bambini and Berman,5 Demkov,6 McCall and Hahn,7 Allen and Eberly,8 and Hioe,9 among others, and have significantly extended it with expressions involving three free parameters and an arbitrary function to an infinite variety of amplitude-and frequency-modulated laser pulses.10 We have found a simple condition which the three essential parameters in the amplitude-and frequency-modulation functions must satisfy in order to achieve a complete population inversion, or to achieve a complete population restoration as in the case of self-induced transparency7 or soliton propagation.

International Meeting on Instabilities and Dynamics of Lasers and Nonlinear Optical Systems•Jan 1, 1985•0 citations

Applications of shaped laser pulses to state-selective excitation and measurement of gas phase collisional dynamics

Mark A. Banash, J. L. Bates, C. P. Lin +1 more

We discuss experimental applications of specific phase and amplitude modulated laser pulse shapes. Electronic transitions in real molecules generally do not have a well-defined Rabi frequency because of the distribution of the orientation of the transition dipole, and because the density of states for all but the very simplest molecules causes many Doppler broadened transitions (including hyperfine components) to overlap. Crafted pulse shapes generate complete population inversions regardless of Rabi frequency, as well as provide a uniform inversion over the pulse bandwidth.1 These experiments directly observe population transfer between frequency ranges by giving two different frequency π pulses at different times—the use of crafted pulses increases signal to noise by now inverting the entire Rabi distribution. Experimental modifications which select a single velocity range in an arbitrarily complex molecule while retaining the other advantages of pulse shaping are presented, and the velocity dependence of fluorescence and coherence lifetimes in molecular gases is analyzed.2 Applications to monitoring velocity-changing collisional dynamics and generating large vibrational population inversions in l2 are presented, as will experimental methods to extend these sequences to more complex molecules, where velocity selection and frequency resolution are not equivalent.

International Laser Science Conference•Jan 1, 1986•0 citations

Effects of arbitrary laser or NMR pulse shapes on population inversion and coherence

Warren S. Warren

We present a new perturbation expansion for calculating the effects of arbitrary pulse shapes in two-level systems, even when the effects are grossly nonlinear. The first two terms have simple physical interpretations. This expansion converges rapidly for all values of resonance offset with simple shapes, and for any pulse shape far from resonance. We generate very simple, symmetric, single phase pulse shapes which produce uniform inversion or polarization and which can be combined into multiple pulse sequences. We also show that pulse shape modification is superior to construction of composite pulse sequences, since such sequences must become erratic far from resonance.

The Journal of Chemical Physics•Dec 15, 1984•210 citations

Understanding of phase modulation in two-level systems through inverse scattering

Andrew Hasenfeld, Sharon Hammes‐Schiffer, Warren S. Warren

Analytical and numerical calculations describe the effects of shaped radiation pulses on two-level systems in terms of quantum-mechanical scattering. Previous results obtained in the reduced case of amplitude modulation are extended to the general case of simultaneous amplitude and phase modulation. We show that an infinite family of phase- and amplitude-modulated pulses all generate rectangular inversion profiles. Experimental measurements also verify the theoretical analysis.

Physical Review A•Sep 1, 1988•13 citations

Implementation of a phase and amplitude modulated π pulse for coherent optical spectroscopy

C. P. Lin, J. L. Bates, J. T. Mayer +1 more

We have implemented an amplitude and phase modulated laser pulse of the form [sech(αt)]1+3i. Such a pulse shape creates uniform population inversion within a selected bandwidth, compensates for Rabi frequency inhomogeneity, and leaves transitions outside the bandwidth unaffected. The unique features of this pulse shape are verified by measuring total fluorescence in iodine vapor as a function of laser power.

The Journal of Chemical Physics•Mar 15, 1987•32 citations

Phase and amplitude near-resonance self-action in periodically modulated laser beams

Vladimir Leonardovich Derbov, Vladislav Viktorovich Serov, Inna L. Plastun +1 more

Full space-time numerical modeling of near-resonance self-action of a beam, whose frequency is harmonically modulated in time, is presented. Maxwell-Bloch equations describing the propagation of the beam through a two-level medium with saturable absorption and refraction are solved using an original stable numerical scheme for multidimensional nonlinear Schrodinger equations. Delayed redistribution of intensity over the beam cross-section due to nonlinear self-focusing and self-phase-modulation effects is shown to affect the phase and the amplitude dynamics of the output signal in a rather nontrivial way, depending on the carrier laser frequency.

International Conference on Transparent Optical Networks•Feb 3, 2004•2 citations
The effects of pulse shapes with simple phase and frequency modulation (phase proportional to amplitude or intensity, frequency proportional to intensity) are explored numerically. Many such shapes can be generated by combining self-phase-modulation with modern laser pulse-shaping capabilities (which are more flexible for amplitude modulation than for frequency modulation). Even though all of these wave forms begin and end at the same frequency (and hence violate the mathematical conditions for adiabatic inversion), we show that they can generate adiabatic population inversion or suppress intramolecular energy redistribution.
We have found new analytic results for a wide variety of atomic excitation processes which involve the use of amplitude-and frequency-modulated laser pulses: (1) We have unified all the previously known solutions including those of Rosen and Zener,1 Landau2 and Zener,3 Rabi,4 Bambini and Berman,5 Demkov,6 McCall and Hahn,7 Allen and Eberly,8 and Hioe,9 among others, and have significantly extended it with expressions involving three free parameters and an arbitrary function to an infinite variety of amplitude-and frequency-modulated laser pulses.10 We have found a simple condition which the three essential parameters in the amplitude-and frequency-modulation functions must satisfy in order to achieve a complete population inversion, or to achieve a complete population restoration as in the case of self-induced transparency7 or soliton propagation.
We discuss experimental applications of specific phase and amplitude modulated laser pulse shapes. Electronic transitions in real molecules generally do not have a well-defined Rabi frequency because of the distribution of the orientation of the transition dipole, and because the density of states for all but the very simplest molecules causes many Doppler broadened transitions (including hyperfine components) to overlap. Crafted pulse shapes generate complete population inversions regardless of Rabi frequency, as well as provide a uniform inversion over the pulse bandwidth.1 These experiments directly observe population transfer between frequency ranges by giving two different frequency π pulses at different times—the use of crafted pulses increases signal to noise by now inverting the entire Rabi distribution. Experimental modifications which select a single velocity range in an arbitrarily complex molecule while retaining the other advantages of pulse shaping are presented, and the velocity dependence of fluorescence and coherence lifetimes in molecular gases is analyzed.2 Applications to monitoring velocity-changing collisional dynamics and generating large vibrational population inversions in l2 are presented, as will experimental methods to extend these sequences to more complex molecules, where velocity selection and frequency resolution are not equivalent.
We present a new perturbation expansion for calculating the effects of arbitrary pulse shapes in two-level systems, even when the effects are grossly nonlinear. The first two terms have simple physical interpretations. This expansion converges rapidly for all values of resonance offset with simple shapes, and for any pulse shape far from resonance. We generate very simple, symmetric, single phase pulse shapes which produce uniform inversion or polarization and which can be combined into multiple pulse sequences. We also show that pulse shape modification is superior to construction of composite pulse sequences, since such sequences must become erratic far from resonance.
Full space-time numerical modeling of near-resonance self-action of a beam, whose frequency is harmonically modulated in time, is presented. Maxwell-Bloch equations describing the propagation of the beam through a two-level medium with saturable absorption and refraction are solved using an original stable numerical scheme for multidimensional nonlinear Schrodinger equations. Delayed redistribution of intensity over the beam cross-section due to nonlinear self-focusing and self-phase-modulation effects is shown to affect the phase and the amplitude dynamics of the output signal in a rather nontrivial way, depending on the carrier laser frequency.