N. N. Rosanov

Diffractive autosolitons in nonlinear interferometers

A theoretical analysis is performed for bistable interferometers in which the dominant mechanism of transverse coupling is diffraction. We propose a model for the diffractive autosoliton as a coupled state of switching waves. Model predictions concerning properties of autosolitons and their interactions are confirmed by computer simulations.

I Transverse Patternsin Wide-Aperture Nonlinear Optical Systems

Publisher Summary This chapter discusses the transverse patterns in wide-aperture nonlinear optical systems, problem of small-scale self-focusing (filamentation or modulational instability) for one and two plane waves, and different types of stable filaments, spatial solitons, whose formation and interaction determine the final form of the filamentation in the wide-aperture system. The chapter examines the different types of spatial patterns that are inherent in systems with feedback. Nonlinear schemes with feedback are characterized by the phenomenon of bistability or multistability. The basic spatiotemporal structures are switching waves that determine the kinetics of switching in spatially distributed nonlinear systems. Filamentation instability is not needed for their formation; hence they can be generated only by a sufficiently large initial perturbation. The examples are switching waves and diffractive autosolitons.

Topologically multicharged and multihumped rotating solitons in wide-aperture lasers with a saturable absorber

We present results of a semianalytical and numerical study of transverse two-dimensional stationary and oscillating solitons in a wide-aperture laser with a saturable absorber and fast nonlinearity of both gain and absorption. We determine the stability conditions and bifurcations of axially symmetric solitons with screw wavefront dislocations of different order. We demonstrate the existence of asymmetric rotating laser solitons with different numbers of intensity maxima.

Extremely short dissipative solitons in an active nonlinear medium with quantum dots

A medium consisting of quartz with embedded active (amplifying) or passive (absorbing) impurities, i.e., quantum dots, is proposed for producing extremely short dissipative solitons on the basis of the effect of enhanced self-induced transparency. The calculations show that, in such a medium, the initial standard femtosecond pulses can be transformed into extremely short dissipative solitons with a peak intensity of ∼1011 W/sm2, with a duration corresponding to the inverse frequency of transitions in impurities, and with the coherent spectral supercontinuum covering almost the entire transmission region of quartz.

Transformation of electromagnetic radiation at moving inhomogeneities of a medium

The possibility of a significant up-conversion of the electromagnetic-radiation frequency due to its Doppler shift by ultrarelativistic nonlinear-medium inhomogeneities induced by high-intensity counterpropagating radiation pulses is analyzed. It is shown that the efficiency of parametric redistribution increases resonantly as the velocity of the inhomogeneity approaches the phase velocity of the high-frequency radiation.

Spatial and temporal structures in cavities with oscillating boundaries

We review the general features of particles, waves and solitons in dynamical cavities formed by oscillating cavity mirrors. Considered are the dynamics of classical particles in one-dimensional geometry of a dynamical billiard, taking into account the non-elastic collisions of particles with mirrors, the (quasi-energy) states of a single quantum particle in a potential well with periodically oscillating wells, and nonlinear structures, including nonlinear Rabi oscillations, cavity optical solitons and solitons of Bose–Einstein condensates, in dynamical cavities or traps.

Maxwell-Drude-Bloch dissipative few-cycle optical solitons

We study the propagation of few-cycle pulses in a two-component medium consisting of nonlinear amplifying and absorbing two-level centers embedded into a linear and conductive host material. First we present a linear theory of propagation of short pulses in a purely conductive material and demonstrate the diffusive behavior for the evolution of the low-frequency components of the magnetic field in the case of relatively strong conductivity. Then, numerical simulations carried out in the frame of the full nonlinear theory involving the Maxwell-Drude-Bloch model reveal the stable creation and propagation of few-cycle dissipative solitons under excitation by incident femtosecond optical pulses of relatively high energies. The broadband losses that are introduced by the medium conductivity represent the main stabilization mechanism for the dissipative few-cycle solitons.

Switching waves, autosolitons, and parallel digital-analogous optical computing

The main features of field structures with characteristics of excitation in wide-aperture nonlinear interferometers driven by coherent external radiation are reviewed. Single and interacting switching waves and diffractive autosolitons are considered, including autosoliton interaction with dislocation of holding radiation wave front. The possibility of realization of digital-analogous parallel optical computing using these structures, spatial hysteresis, and reconstruction of interferometer regime under effect of radiation are discussed.

Attractors and chaos of electron dynamics in electromagnetic standing waves

Abstract In an electromagnetic standing wave formed by two super-intense colliding laser pulses, radiation reaction totally modifies the electron motion. The quantum corrections to the electron motion and the radiation reaction force can be independently small or large, depending on the laser intensity and wavelength, thus dividing the parameter space into 4 domains. The electron motion evolves to limit cycles and strange attractors when radiation reaction dominates. This creates a new framework for high energy physics experiments on the interaction of energetic charged particle beams and colliding super-intense laser pulses.

Generation of unipolar pulses in nonlinear media

Methods recently proposed for generating unipolar pulses in nonlinear media in terahertz and optical electromagnetic ranges are reviewed. Such pulses have nonzero “electric area” (time integral of the field strength over the entire duration of a pulse) and, correspondingly, a significant component of the field with zero frequency, thus exhibiting quasistatic properties. Effective generation of unipolar pulses would allow, e.g., transferring mechanical momentum to charged particles and, thereby, controlling the motion of wave packets of matter, which can be useful for compact accelerators of charged particles and for other applications.