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

Linear and nonlinear optical precursors in inhomogeneously broadened two-level media

Robert Marskar, Ulf L. Österberg

Published Dec 20, 2012• 3 citations
Publisher

Abstract

By solving the two-level Maxwell-Bloch equations for resonant pulses numerically, we observe precursors in a regime where the area theorem is fulfilled. The precursors are $0\ensuremath{\pi}$ pulses traveling at a velocity close to the speed of light, and the main signal is a self-induced transparency (SIT) $2\ensuremath{\pi}$ soliton traveling at a much lower velocity. The manifestation of the precursors is strongest when the input pulse duration is on the same order as the inhomogeneous lifetime and the input area is close to $\ensuremath{\pi}$. Depending on the relationship between the input pulse duration and the inhomogeneous lifetime, the precursors can interact linearly or nonlinearly with the material. Experimental confirmation of these results should offer a direct and reasonably straightforward way of measuring optical precursors.

DOI
10.1103/physreva.86.063826

Related papers

Few-cycle self-induced-transparency solitons

Yuan-Yao Lin, I-Hong Chen, Ray‐Kuang Lee

We reveal the existence of an optical self-induced-transparency soliton family in a two-level absorbing system down to the few-cycle limit. Based on the few-cycle envelope approximation, we introduce a systematical method of reducing the Maxwell-Bloch equations beyond the slowly varying envelope approximation and characterize the parameter space to achieve slow and fast lights. Verified by direct numerical simulations with full vectorial Maxwell-Bloch equations, we also give the relationships for a number of optical cycles on area theory and pulse group velocity, which demonstrate possible coherent photon-matter interactions.

Physical Review A•Apr 21, 2011•16 citations

Effects of spatial dispersion on Self--induced transparency in two--level media

Zoran M. Ivić, Dalibor Čevizović, Željko Pržulj +2 more

We study the effects of dispersion in carrier waves on the properties of soliton self--induced transparency (SIT) in two level media. We found substantial impact of dispersion effects on typical SIT soliton features. For example, the degree of SIT pulse velocity slowing down (acceleration) is determined by the ratio of the incoming pulse frequency over atomic transition frequency - $x=ω/ω_0$. Specifically, an immediate pulse stopping is predicted for absorbing media when pulse duration time exceeds some critical value. In the sharp line limit stopping may emerge only for frequency ratio above unity, while for the inhomogeneously broadened systems it appears irrespective of the value of $x$. Analysis performed on the basis of Mcall\& Hahn \textit{Area theorem} implies that pulse stopping is achieved when Ber's absorption coefficient approaches infinity, that is, pulse energy is fully absorbed in the medium. In the case of amplifying media super-luminal motion is predicted as in the case of resonance. However, there is a lowest value in the frequency ratio below which the pulse velocity tends to the sub-luminal region. These new features of the SIT phenomenon open novel ways on how it may be exploited for the control of electromagnetic wave radiation in two-level media. This may be achieved by varying frequency ratio.

arXiv:1909.01393•Sep 3, 2019•0 citations

Controllable interaction of counterpropagating solitons in three-level media

Andreas Pusch, Joachim M. Hamm, Ortwin G. Hess

We examine the dynamics of counterpropagating self-induced transparency solitons in three-level media. In a multilevel system, self-induced transparency gives rise to soliton solutions if the propagation is unidirectional, but the collision of counterpropagating pulses destroys the integrability of the underlying equations. We consider the collision of a rightward and a leftward moving self-induced transparency solitary wave by solving the full Maxwell-Bloch equations numerically using a finite-difference time-domain approach. Depending on pulse duration, amplitude and relative polarizations of the initial solitary waves we observe different regimes of interaction. For high group velocities and orthogonal polarizations, secondary solitary waves are born during the interaction, whereas the collision of solitary waves with the same polarization never produces secondary solitary waves but leaves behind a population grating in the interaction region. Because the crucial parameters can be controlled, an experimental confirmation of the predicted interaction regimes should be feasible.

Physical Review A•Aug 11, 2010•17 citations

Two-photon self-induced transparency in a resonant medium. I. Analytical treatment

N Tan-no, Kenichi Yokoto, Humio Inaba

The authors develop a theoretical analysis which describes coherent nonlinear resonant effects where two optical pulses of different frequencies undergo two-photon self-induced transparency (two-photon SIT) in an inhomogeneously broadened three-level system. The field (Maxwell) and atomic (Schrodinger; density matrix representation) equations are coupled in a self-consistent manner by virtue of the resultant macroscopic polarizations at the two frequencies. This treatment is accomplished under circumstances where atomic coherence plays a predominant role. The resulting equations yield a new two-photon area theorem which gives first the intensity dependent, two-photon absorption law analogous to Beer's law for the one-photon transition. Secondly, a 2 pi Lorentzian pulse solution is derived which propagates without loss at the modified pulse velocity.

Journal of Physics B Atomic and Molecular Physics•Feb 21, 1975•23 citations

Coexistence of a self-induced transparency soliton and a Bragg soliton

Hong‐Yih Tseng, Sien Chi

We theoretically show that a self-induced transparency (SIT) soliton and a Bragg soliton can coexist in a nonlinear photonic band gap (PBG) medium doped uniformly with inhomogeneous-broadening two-level atoms. The Maxwell-Bloch equations for the pulse propagating through such a uniformly doped PBG structure are derived first and further reduced to an effective nonlinear Schrödinger equation. This model describes an equivalent physical mechanism for a Bragg-soliton propagation resulting from the effective quadratic dispersion balancing with the effective third-order nonlinearity. Because the resonant atoms are taken into account, the original band gap can be shifted both by the dopants and the instantaneous nonlinearity response originating from an intense optical pulse. As a result, even if a SIT soliton with its central frequency deep inside the original forbidden band, it still can propagate through the resonant PBG medium as long as this SIT soliton satisfies the effective Bragg-soliton propagation. An approximate soliton solution describing such coexistence is found. We also show that the pulse width and group velocity of this soliton solution can be uniquely determined for given material parameters, atomic transition frequency, and input central frequency of the soliton. The numerical examples of the SIT soliton in a one-dimensional As2S3-based PBG structure doped uniformly with Lorentzian line-shape resonant atoms are shown. It is found that a SIT soliton with approximately 100-ps width in such a resonant PBG structure can travel with the velocity being two orders of magnitude slower than the light speed in an unprocessed host medium.

Physical review. E, Statistical physics, plasmas, fluids, and related interdisciplinary topics•Nov 20, 2002•8 citations

Coupled Maxwell-Bloch equations with inhomogeneous broadening for a 3-level system

Sarbarish Chakravarty, B. Prinari, Mark J. Ablowitz

The phenomenon that describes the effect of a coherent medium response to an incident electric field, to which the medium is totally transparent and which undergoes lossless propagation, is known as self-induced transparency (SIT). SIT was first discovered by McCall and Hahn (1969) in the case of nondegenerate two-level atoms. Special solutions for the two-level system were found by Lamb (1971), while the initial value problem for the propagation of a pulse through a resonant two-level optical medium was solved by Inverse Scattering Transform (IST) in [1, 2]. It is possible to formulate the SIT equations in the framework of the IST also in the case of a three-level system, as in [3]. While the associated scattering problem is the same as for the coupled nonlinear Schrödinger equation, the time evolution depends on asymptotic values of the material polarizability envelopes and is highly non-trivial. This talk will address the solution of the initial value problem for the SIT equations for three level systems, for generic preparation of the medium, and

•Jan 1, 2003•0 citations
By solving the two-level Maxwell-Bloch equations for resonant pulses numerically, we observe precursors in a regime where the area theorem is fulfilled. The precursors are 0\ensuremathπ0\ensuremath{\pi}0\ensuremathπ pulses traveling at a velocity close to the speed of light, and the main signal is a self-induced transparency (SIT) 2\ensuremathπ2\ensuremath{\pi}2\ensuremathπ soliton traveling at a much lower velocity. The manifestation of the precursors is strongest when the input pulse duration is on the same order as the inhomogeneous lifetime and the input area is close to \ensuremathπ\ensuremath{\pi}\ensuremathπ. Depending on the relationship between the input pulse duration and the inhomogeneous lifetime, the precursors can interact linearly or nonlinearly with the material. Experimental confirmation of these results should offer a direct and reasonably straightforward way of measuring optical precursors.
We reveal the existence of an optical self-induced-transparency soliton family in a two-level absorbing system down to the few-cycle limit. Based on the few-cycle envelope approximation, we introduce a systematical method of reducing the Maxwell-Bloch equations beyond the slowly varying envelope approximation and characterize the parameter space to achieve slow and fast lights. Verified by direct numerical simulations with full vectorial Maxwell-Bloch equations, we also give the relationships for a number of optical cycles on area theory and pulse group velocity, which demonstrate possible coherent photon-matter interactions.
We study the effects of dispersion in carrier waves on the properties of soliton self--induced transparency (SIT) in two level media. We found substantial impact of dispersion effects on typical SIT soliton features. For example, the degree of SIT pulse velocity slowing down (acceleration) is determined by the ratio of the incoming pulse frequency over atomic transition frequency - x=ω/ω0x=ω/ω_0x=ω/ω0​. Specifically, an immediate pulse stopping is predicted for absorbing media when pulse duration time exceeds some critical value. In the sharp line limit stopping may emerge only for frequency ratio above unity, while for the inhomogeneously broadened systems it appears irrespective of the value of xxx. Analysis performed on the basis of Mcall\& Hahn \textit{Area theorem} implies that pulse stopping is achieved when Ber's absorption coefficient approaches infinity, that is, pulse energy is fully absorbed in the medium. In the case of amplifying media super-luminal motion is predicted as in the case of resonance. However, there is a lowest value in the frequency ratio below which the pulse velocity tends to the sub-luminal region. These new features of the SIT phenomenon open novel ways on how it may be exploited for the control of electromagnetic wave radiation in two-level media. This may be achieved by varying frequency ratio.
We examine the dynamics of counterpropagating self-induced transparency solitons in three-level media. In a multilevel system, self-induced transparency gives rise to soliton solutions if the propagation is unidirectional, but the collision of counterpropagating pulses destroys the integrability of the underlying equations. We consider the collision of a rightward and a leftward moving self-induced transparency solitary wave by solving the full Maxwell-Bloch equations numerically using a finite-difference time-domain approach. Depending on pulse duration, amplitude and relative polarizations of the initial solitary waves we observe different regimes of interaction. For high group velocities and orthogonal polarizations, secondary solitary waves are born during the interaction, whereas the collision of solitary waves with the same polarization never produces secondary solitary waves but leaves behind a population grating in the interaction region. Because the crucial parameters can be controlled, an experimental confirmation of the predicted interaction regimes should be feasible.
The authors develop a theoretical analysis which describes coherent nonlinear resonant effects where two optical pulses of different frequencies undergo two-photon self-induced transparency (two-photon SIT) in an inhomogeneously broadened three-level system. The field (Maxwell) and atomic (Schrodinger; density matrix representation) equations are coupled in a self-consistent manner by virtue of the resultant macroscopic polarizations at the two frequencies. This treatment is accomplished under circumstances where atomic coherence plays a predominant role. The resulting equations yield a new two-photon area theorem which gives first the intensity dependent, two-photon absorption law analogous to Beer's law for the one-photon transition. Secondly, a 2 pi Lorentzian pulse solution is derived which propagates without loss at the modified pulse velocity.
We theoretically show that a self-induced transparency (SIT) soliton and a Bragg soliton can coexist in a nonlinear photonic band gap (PBG) medium doped uniformly with inhomogeneous-broadening two-level atoms. The Maxwell-Bloch equations for the pulse propagating through such a uniformly doped PBG structure are derived first and further reduced to an effective nonlinear Schrödinger equation. This model describes an equivalent physical mechanism for a Bragg-soliton propagation resulting from the effective quadratic dispersion balancing with the effective third-order nonlinearity. Because the resonant atoms are taken into account, the original band gap can be shifted both by the dopants and the instantaneous nonlinearity response originating from an intense optical pulse. As a result, even if a SIT soliton with its central frequency deep inside the original forbidden band, it still can propagate through the resonant PBG medium as long as this SIT soliton satisfies the effective Bragg-soliton propagation. An approximate soliton solution describing such coexistence is found. We also show that the pulse width and group velocity of this soliton solution can be uniquely determined for given material parameters, atomic transition frequency, and input central frequency of the soliton. The numerical examples of the SIT soliton in a one-dimensional As2S3-based PBG structure doped uniformly with Lorentzian line-shape resonant atoms are shown. It is found that a SIT soliton with approximately 100-ps width in such a resonant PBG structure can travel with the velocity being two orders of magnitude slower than the light speed in an unprocessed host medium.
The phenomenon that describes the effect of a coherent medium response to an incident electric field, to which the medium is totally transparent and which undergoes lossless propagation, is known as self-induced transparency (SIT). SIT was first discovered by McCall and Hahn (1969) in the case of nondegenerate two-level atoms. Special solutions for the two-level system were found by Lamb (1971), while the initial value problem for the propagation of a pulse through a resonant two-level optical medium was solved by Inverse Scattering Transform (IST) in [1, 2]. It is possible to formulate the SIT equations in the framework of the IST also in the case of a three-level system, as in [3]. While the associated scattering problem is the same as for the coupled nonlinear Schrödinger equation, the time evolution depends on asymptotic values of the material polarizability envelopes and is highly non-trivial. This talk will address the solution of the initial value problem for the SIT equations for three level systems, for generic preparation of the medium, and