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

Annual Meeting Optical Society of America

Spatio–temporal instabilities in far infrared Raman lasers

Suranjana Rai, Jagdish Rai, Jerald R. Izatt

Published Jan 1, 1991• 0 citations
Publisher

Abstract

Raman lasers operating in the far infrared are well described by the three- and four-level molecular systems. The theoretical analysis of these lasers is based on a density matrix treatment. Steady-state and time dynamics of these systems has been studied extensively. However, their spatial aspects involving propagation are not well understood. In this paper, we study the spatial and temporal dynamics of these lasers based on a density matrix analysis for the four-level molecular systems. The full set of Maxwell-Bloch equation consists of sixteen equations. We obtain the numerical solutions for this system and analyze regions of phase space where the laser fields show chaotic behavior.

DOI
10.1364/oam.1991.fn6

Related papers

Chaos in the Four-Level Raman Far-Infrared Lasers

Suranjana Raj, Jerald R. Izatt, Jagdish Rai +1 more

The full set of Maxwell-Bloch equations for the four-level atomic systems is numerically integrated to obtain the time dynamics. Specific applications to the CH3F optically pumped far-infrared lasers are considered.

Nonlinear Dynamics in Optical Systems•Jan 1, 1990•0 citations

Interaction of three coherent fields with Doppler broadened serial four-level systems: Application to four-level FIR lasers

G.-D. Willenberg, J. Heppner, Frank B. Foote

The semiclassical density matrix treatment is applied to serial four-level systems for the steady state. Phase and energy relaxations as well as Doppler effects andMdegeneracy are accounted for. The calculations are restricted to parallel polarized fields, avoiding problems of quantum interference. The formalism is used to calculate the gain spectra of different four-level far-infrared (FIR) laser schemes: double resonance pumped laser, Raman laser, two-photon pumped laser, and hyper-Raman-laser.

IEEE Journal of Quantum Electronics•Dec 1, 1982•28 citations

Dynamical behavior of two-color ultrashort laser pulses in a cascade three-level molecular system

Chuan‐Kui Wang

Using the finite-difference time domain technique(FDTD) for the fields and the predictor-corrector method for the material variables,we solve the Maxwell-Bloch equations beyond the slowly-varying envelope approximation and the rotating-wave approximation.4,4′-bis(dimethylamino) stilbene organic molecule is one type of one-dimensional symmetrical system and its electronic structure and parameters are calculated by density functional theory.The molecule can be simplified as a three-level system.By numerically simulating the propagation of two-color 2π ultrashort laser pulses in a cascade three-level organic molecule system,we analyze the temporal-spatial evolution properties of the ultrashort laser pulses and the population of each energy level under different resonant conditions.

Journal of Atomic and Molecular Physics•Jan 1, 2006•0 citations

On the non-linear spectroscopy including saturated absorption and four-wave mixing in two and multi-level atoms: a computational study

M Patel, Gerhard De Jager, Z Nkosi +2 more

In this paper we report on the study of two and multi-level atoms interacting with multiple laser beams. The semi-classical approach is used to describe the system in which the atoms are treated quantum mechanically via the density matrix operator, while the laser beams are treated classically using Maxwells equations. We present results of a two level atom interacting with single and multiple laser beams and demonstrate Rabi oscillations between the levels. The effects of laser modulation on the dynamics of the atom (atomic populations and coherences) are examined by solving the optical Bloch equations. Plots of the density matrix elements as a function of time are presented for various parameters such as laser intensity, detuning, modulation etc. In addition, phase-space plots and Fourier analysis of the density matrix elements are provided. The atomic polarization, estimated from the coherence terms of the density matrix elements, is used in the numerical solution of Maxwells equations to determine the behaviour of the laser beams as they propagate through the atomic ensemble. The effects of saturation and hole-burning are demonstrated in the case of two counter propagating beams with one being a strong beam and the other being very weak. The above work is extended to include four-wave mixing in four level atoms in a diamond configuration. Two co-propagating beams of different wavelengths drive the atoms from a ground state |1〉 to an excited state |3〉 via an intermediate state |2〉. The atoms then move back to the ground state via another intermediate state |4〉, resulting in the generation of two additional correlated photon beams. The characteristics of these additional photons are studied.

Journal of Physics Conference Series•Oct 1, 2017•0 citations

Spontaneous spatial pattern formation in wide gain section lasers

S.G. Wenden, Per Kristen Jakobsen, J. V. Moloney

Two-level and Raman lasers with wide-gain sections undergo spontaneous symmetry breaking beyond the first laser threshold resulting in an off-axis emission that, if stable, would correspond to a ring in the far field. The angle subtended by the emission to the laser axis depends on the laser detuning, polarization decay time, and size of the laser cross-section. Optical vortices, propagating fronts, and complex spatio–temporal patterns are predicted to emerge at the first and second thresholds. The intensity dependent detuning and pump laser transverse profile in the Raman laser offers a fascinating array of pattern forming possibilities involving coexisting dark and bright waves. When the polarization decays much faster than the cavity field and medium inversion, one usually adiabatically eliminates this variable from the Maxwell-Bloch equations. Inclusion of transverse effects in this limit, however, leads to spurious transverse instabilities that can be mistaken for numerical grid oscillations. Decoupling of the polarization variable from the electric field allows arbitrarily high transverse wavenumbers to grow.

Annual Meeting Optical Society of America•Jan 1, 1991•0 citations

Nonlinear dynamics of Raman lasers

Weiping Lu, Robert G. Harrison

Detailed analysis of the steady-state and dynamical unstable behavior of single-mode, homogeneously broadened Raman lasers is presented. Bistable features of the Raman emission and its operating conditions are determined from steady-state analysis. Parametrization of the dynamical behavior shows instabilities to exist over a broad range of operation conditions and for broad cavity detuning to the low-frequency side of the gain center where the bistable emission also prevails. Notably, period-doubling routes to chaos and sustained oscillatory behavior in both intensity and phase are found to occur for both good and bad cavity conditions, the dynamics of the phase revealing additional temporal features to that of intensity.

Physical Review A•Jun 1, 1991•20 citations
Raman lasers operating in the far infrared are well described by the three- and four-level molecular systems. The theoretical analysis of these lasers is based on a density matrix treatment. Steady-state and time dynamics of these systems has been studied extensively. However, their spatial aspects involving propagation are not well understood. In this paper, we study the spatial and temporal dynamics of these lasers based on a density matrix analysis for the four-level molecular systems. The full set of Maxwell-Bloch equation consists of sixteen equations. We obtain the numerical solutions for this system and analyze regions of phase space where the laser fields show chaotic behavior.
The semiclassical density matrix treatment is applied to serial four-level systems for the steady state. Phase and energy relaxations as well as Doppler effects andMdegeneracy are accounted for. The calculations are restricted to parallel polarized fields, avoiding problems of quantum interference. The formalism is used to calculate the gain spectra of different four-level far-infrared (FIR) laser schemes: double resonance pumped laser, Raman laser, two-photon pumped laser, and hyper-Raman-laser.
Using the finite-difference time domain technique(FDTD) for the fields and the predictor-corrector method for the material variables,we solve the Maxwell-Bloch equations beyond the slowly-varying envelope approximation and the rotating-wave approximation.4,4′-bis(dimethylamino) stilbene organic molecule is one type of one-dimensional symmetrical system and its electronic structure and parameters are calculated by density functional theory.The molecule can be simplified as a three-level system.By numerically simulating the propagation of two-color 2π ultrashort laser pulses in a cascade three-level organic molecule system,we analyze the temporal-spatial evolution properties of the ultrashort laser pulses and the population of each energy level under different resonant conditions.
In this paper we report on the study of two and multi-level atoms interacting with multiple laser beams. The semi-classical approach is used to describe the system in which the atoms are treated quantum mechanically via the density matrix operator, while the laser beams are treated classically using Maxwells equations. We present results of a two level atom interacting with single and multiple laser beams and demonstrate Rabi oscillations between the levels. The effects of laser modulation on the dynamics of the atom (atomic populations and coherences) are examined by solving the optical Bloch equations. Plots of the density matrix elements as a function of time are presented for various parameters such as laser intensity, detuning, modulation etc. In addition, phase-space plots and Fourier analysis of the density matrix elements are provided. The atomic polarization, estimated from the coherence terms of the density matrix elements, is used in the numerical solution of Maxwells equations to determine the behaviour of the laser beams as they propagate through the atomic ensemble. The effects of saturation and hole-burning are demonstrated in the case of two counter propagating beams with one being a strong beam and the other being very weak. The above work is extended to include four-wave mixing in four level atoms in a diamond configuration. Two co-propagating beams of different wavelengths drive the atoms from a ground state |1〉 to an excited state |3〉 via an intermediate state |2〉. The atoms then move back to the ground state via another intermediate state |4〉, resulting in the generation of two additional correlated photon beams. The characteristics of these additional photons are studied.
Two-level and Raman lasers with wide-gain sections undergo spontaneous symmetry breaking beyond the first laser threshold resulting in an off-axis emission that, if stable, would correspond to a ring in the far field. The angle subtended by the emission to the laser axis depends on the laser detuning, polarization decay time, and size of the laser cross-section. Optical vortices, propagating fronts, and complex spatio–temporal patterns are predicted to emerge at the first and second thresholds. The intensity dependent detuning and pump laser transverse profile in the Raman laser offers a fascinating array of pattern forming possibilities involving coexisting dark and bright waves. When the polarization decays much faster than the cavity field and medium inversion, one usually adiabatically eliminates this variable from the Maxwell-Bloch equations. Inclusion of transverse effects in this limit, however, leads to spurious transverse instabilities that can be mistaken for numerical grid oscillations. Decoupling of the polarization variable from the electric field allows arbitrarily high transverse wavenumbers to grow.
Detailed analysis of the steady-state and dynamical unstable behavior of single-mode, homogeneously broadened Raman lasers is presented. Bistable features of the Raman emission and its operating conditions are determined from steady-state analysis. Parametrization of the dynamical behavior shows instabilities to exist over a broad range of operation conditions and for broad cavity detuning to the low-frequency side of the gain center where the bistable emission also prevails. Notably, period-doubling routes to chaos and sustained oscillatory behavior in both intensity and phase are found to occur for both good and bad cavity conditions, the dynamics of the phase revealing additional temporal features to that of intensity.