Stimulated Raman Self-scattering Research Articles

Effect of Stimulated Raman Self-Scattering on the Dynamics of Pulses in a Gradient Waveguide

Effect of Stimulated Raman Self-Scattering on the Dynamics of Pulses in a Gradient Waveguide

Investigating the Dynamics of the Propagation of Intense Pulses in a Photonic Crystal Fiber

An analytical study is performed on the stability of soliton-like pulses propagating in a fiber in the mode of tunneling ionization and stimulated Raman self-scattering. It is shown that the mutual compensation of these effects is possible under certain conditions for the parameters of the medium and the signal.

The Evolution of High-Intensity Light Pulses in a Nonlinear Medium Taking into Account the Raman Effect

In this paper, we study the evolution of intensive light pulses in nonlinear single-mode fibers. The dynamics of light in such fibers is described by the nonlinear Schr\"odinger equation with the Raman term, due to stimulated Raman self-scattering. It is shown that dispersive shock waves are formed during the evolution of sufficiently intensive pulses. In this case, the situation is much richer than for the nonlinear Schr\"odinger equation with Kerr nonlinearity only. The Whitham equations are obtained under the assumption that the Raman term can be considered as a small perturbation. These equations describe slow evolution of dispersive shock waves. It is shown that if one takes into account the Raman effect, then dispersive shock waves can asymptotically acquire a stationary profile. The analytical theory is confirmed by numerical calculations.

Analytic description of laser pulse propagation in gas-filled hollow-core photonic crystal fibre

With the help of the moment method, we analyze pulse propagation in Raman-active gas-filled hollow-core photonic crystal fiber under the influence of tunnel ionization effects. We obtain explicit conditions at which photoionization is able to suppress frequency shift induced by stimulated Raman self-scattering. An approximate analytic solution for all pulse parameters following the quasi-stabilization regime is obtained for arbitrary propagation distances.

Stabilization of Optical Pulse Propagation in a Regime of Ionization and Stimulated Raman Self-Scattering

Dynamics of the propagation of soliton-like pulses in a regime of tunnel ionization and stimulated Raman self-scattering is described analytically. It is shown that the mutual compensation of these effects stabilizes signal parameters. The corresponding formulas for pulse duration are obtained.

Эволюция интенсивных световых импульсов в нелинейной среде с учетом эффекта Рамана

AbstractThe evolution of high-intensity light pulses in nonlinear single-mode optical waveguides, the dynamics of light in which is described by the nonlinear Schrödinger equation with a Raman term taking into account stimulated Raman self-scattering of light, is investigated. It is demonstrated that dispersive shock waves the behavior of which is much more diverse than in the case of ordinary nonlinear Schrödinger equation with a Kerr nonlinearity are formed in the process of evolution of pulses of substantially high intensity. The Whitham equations describing slow evolution of the dispersive shock waves are derived under the assumption of the Raman term being small. It is demonstrated that the dispersive shock waves can asymptotically assume a stationary profile when the Raman effect is taken into account. Analytical theory is corroborated by numerical calculations.

Soliton generation via stimulated Brillouin self-scattering under slow light conditions

Acousto-optic soliton generation via stimulated Brillouin self-scattering is predicted for light propagating at the speed of sound under electromagnetically induced transparency conditions. As in stimulated Raman self-scattering, the frequency of the electromagnetic component is gradually Stokes shifted as its intensity increases; the acoustic component has no carrier frequency. This phenomenon is explained by the possibility of forward stimulated Brillouin scattering, which is forbidden in nondispersive media. In contrast to stimulated Raman self-scattering, the Stokes shift of the electromagnetic component approaches a constant limit after the pulse has propagated to a certain distance. It is shown that the predicted soliton generation does not involve any threshold condition and can occur at extremely low input pulse intensities.

Continuous Stokes self-scattering of an optical pulse in a uniaxial crystal in the case of Zakharov—Benney resonance

A new mechanism of the continuous frequency down-conversion of a pulse propagating in a uniaxial crystal under conditions of the Zakharov—Benney resonance between its ordinary and extraordinary components is proposed. Unlike stimulated Raman self-scattering, here the red frequency shift of the ordinary component saturates, achieving its maximum value at some propagation length, which is proportional to the input pulse intensity. The ordinary component generates an ultimately short single pulse of the extraordinary wave propagating in the soliton regime. It is shown that this effect can be observed only in a crystal with the positive birefringence.

Stimulated Raman self-scattering of femtosecond pulses. II. The self-compression of Schrödinger solitons in a spectrally inhomogeneous dispersion medium

It is shown that stimulated Raman self-scattering (SRSS) can be efficiently used for the compression of femtosecond optical solitons in optical fibres with the spectrally inhomogeneous frequency dependence of the group-velocity dispersion. The SRS dynamics is studied in detail near the point of the second-order zero dispersion. The saturation of compression of femtosecond solitons in spectrally inhomogeneous fibres in the zero-dispersion region is predicted.

Stimulated Raman self-scattering of femtosecond pulses. I. Soliton and non-soliton regimes of coherent self-scattering

Stimulated Raman self-scattering (SRSS) is shown not to be a unique effect observed exclusively in the propagation of femtosecond optical solitons through optical fibres. SRSS always accompanies the self-action of high-power femtosecond pulses in a variety of media. Unlike classical SRS, SRSS has no lasing threshold and can appear when the pulse spectrum overlaps the band of vibrational resonances of the medium. A classification of the main SRSS regimes is given. The basic features of different regimes of ultrashort-pulse self-scattering are investigated by computer simulation techniques.

Erratum: Stimulated Raman self-scattering of laser pulses [Sov. J. Quantum Electron. 19, 391–392 (March 1989)

Erratum: Stimulated Raman self-scattering of laser pulses [Sov. J. Quantum Electron. 19, 391–392 (March 1989)

Stimulated Raman self-scattering of laser pulses

A theoretical investigation is reported of stimulated Raman self-scattering (self-STRS) of laser pulses. It is shown that the simultaneous effects of phase self-modulation and of the dispersion in the spectral range of negative dispersion of the group velocities enhance the efficiency of self-STRS, whereas in the positive dispersion range these effects suppress self-STRS. The observed STRS spectra of fiber waveguides are studied.

Nonlinear pairing of short bright and dark soliton pulses by phase cross modulation

The possibility of nonlinear pairing of bright and dark optical solitons at the wave phase cross modulation in a nonlinear dispersive medium is shown. The realization of fundamentally novel methods for the stabilization of powerful wave packets in the positive and negative group velocity dispersion regions of the interacting waves with different colors is demonstrated. The dynamics of coupling dark and bright optical solitons in frames of a system of two bound nonlinear Schrodinger equations are investigated analytically and numerically. The role of disturbing factors, linear absorption, duration, pulse position, and nonlinearity mismatch are discussed. The influence of the stimulated Raman self-scattering effect and modulation instability on the dynamics of bright and dark soliton pairing is investigated. The process of soliton collision is studied. >