Showing papers by "Yuri S. Kivshar published in 2002"
TL;DR: In this article, the authors derived effective discrete equations with long-range interaction for describing the waveguide modes and demonstrate that they provide a highly accurate generalization of the familiar tight-binding models that are employed, e.g., for the study of coupled-resonator optical waveguides.
Abstract: We study light transmission in two-dimensional photonic-crystal waveguides with embedded nonlinear defects. First, we derive effective discrete equations with long-range interaction for describing the waveguide modes and demonstrate that they provide a highly accurate generalization of the familiar tight-binding models that are employed, e.g., for the study of coupled-resonator optical waveguides. Using these equations, we investigate the properties of straight waveguides and waveguide bends with embedded linear and nonlinear defects. We emphasize the role of evanescent modes in the transmission properties of such waveguides and demonstrate the possibility of the nonlinearity-induced bistable (all-optical switcher) and unidirectional (optical diode) transmission. Additionally, we demonstrate adaptability of our approach for investigation of multimode waveguides by the example of the bound states in their constrictions.
203 citations
TL;DR: The ringlike soliton clusters provide a nontrivial generalization of the concepts of two-soliton spiraling, optical vortex solitons, and necklace-type optical beams.
Abstract: We introduce the concept of soliton clusters--multisoliton bound states in a homogeneous bulk optical medium--and reveal a key physical mechanism for their stabilization associated with a staircaselike phase distribution that induces a net angular momentum and leads to cluster rotation. The ringlike soliton clusters provide a nontrivial generalization of the concepts of two-soliton spiraling, optical vortex solitons, and necklace-type optical beams.
116 citations
TL;DR: A novel concept of diffraction management in waveguide arrays is suggested and the existence of discrete gap solitons that possess the properties of both conventional discrete and Bragg gratingsolitons are predicted.
Abstract: We suggest a novel concept of diffraction management in waveguide arrays and predict the existence of discrete gap solitons that possess the properties of both conventional discrete and Bragg grating solitons. We demonstrate that one can control both the soliton velocity and the propagation direction by varying the input light intensity.
103 citations
TL;DR: In this article, the transmission of a layered photonic structure (a one-dimensional photonic crystal) consisting of alternating slabs of two materials with positive and negative refractive index was analyzed.
Abstract: We analyze transmission of a layered photonic structure (a one-dimensional photonic crystal) consisting of alternating slabs of two materials with positive and negative refractive index. For the periodic structure with zero averaged refractive index, we demonstrate a number of unique properties of the beam transmission observed in strong beam modification and reshaping.
97 citations
TL;DR: In this article, the interaction of dark solitons with a localized impurity in Bose-Einstein condensates was studied analytically, and the results were verified by direct numerical simulations of the Gross-Pitaevskii equation.
Abstract: We study the interaction of dark solitons with a localized impurity in Bose-Einstein condensates. We apply the soliton perturbation theory developed earlier in optics for describing the soliton dynamics and soliton-impurity interaction analytically, and then verify the results by direct numerical simulations of the Gross-Pitaevskii equation. We find that a dark soliton can be reflected from or transmitted through a repulsive impurity in a controllable manner, while near the critical point the soliton can be quasitrapped by the impurity. Additionally, we demonstrate that an immobile soliton may be captured and dragged by an adiabatically moving attractive impurity.
85 citations
TL;DR: In this article, the properties of nonlinear guided waves and (bright and dark) spatial optical solitons in a periodic medium created by linear and nonlinear waveguides are discussed.
Abstract: We present an overview of the properties of nonlinear guided waves and (bright and dark) spatial optical solitons in a periodic medium created by linear and nonlinear waveguides. First we consider a single layer with a cubic nonlinear response (a nonlinear slab waveguide) embedded in a periodic layered linear medium and describe nonlinear localized modes (guided waves and Bragg-like localized gap modes) and their stability. Then we study modulational instability as well as the existence and stability of discrete spatial solitons in a periodic array of identical nonlinear layers, a one-dimensional model of nonlinear photonic crystals. We emphasize both similarities to and differences from the models described by the discrete nonlinear Schrodinger equation, which is derived in the tight-binding approximation, and the coupled-mode theory, which is valid for shallow periodic modulations.
83 citations
TL;DR: Spatial optical solitons in a one-dimensional nonlinear photonic crystal created by an array of thin-film nonlinear waveguides, the so-called Dirac-comb nonlinear lattice are studied.
Abstract: We study spatial optical solitons in a one-dimensional nonlinear photonic crystal created by an array of thin-film nonlinear waveguides, the so-called Dirac-comb nonlinear lattice We analyze modulational instability of the extended Bloch-wave modes and also investigate the existence and stability of bright, dark, and "twisted" spatially localized modes in such periodic structures Additionally, we discuss both similarities and differences of our general results with the simplified models of nonlinear periodic media described by the discrete nonlinear Schrodinger equation, derived in the tight-binding approximation, and the coupled-mode theory, valid for shallow periodic modulations of the optical refractive index
78 citations
TL;DR: In this paper, the nonlinear properties of photonic crystals and photonic-crystal waveguides were exploited to create the all-optical analogs of diodes and transistors that will one day enable the first alloptical computer to be built.
Abstract: Photonic crystals, an analog of semiconductors for light waves, are composite periodic dielectric materials that provide novel and unique ways to control many aspects of electromagnetic radiation. Harnessing the nonlinear properties of photonic crystals and photonic-crystal waveguides offers an opportunity to create the all-optical analogs of diodes and transistors that will one day enable the first all-optical computer to be built.
77 citations
TL;DR: An improved analytical model is suggested that describes the growth of single waveguides and the main features of their interaction in photosensitive materials.
Abstract: We study the optically induced growth and interaction of self-written waveguides in a photopolymerizable resin. We investigate experimentally how the interaction depends on the mutual coherence and the relative power of the input beams and suggest an improved analytical model that describes the growth of single waveguides and the main features of their interaction in photosensitive materials.
69 citations
TL;DR: In this article, the properties of composite (or vector) spatial optical solitons created by the incoherent interaction of two optical beams and associated with higher-order modes guided by a soliton-induced waveguide in a bulk medium are discussed.
Abstract: We discuss the properties of composite (or vector) spatial optical solitons created by the incoherent interaction of two optical beams and associated with higher-order modes guided by a soliton-induced waveguide in a bulk medium. Such stationary (2+1)-dimensional self-trapped localized structures include, in particular, vortex- and dipole-mode vector solitons and also incorporate higher-order multipole spatial solitons in a bulk medium, such as quadrupole solitons and necklace-type composite beams. We overview our theoretical and experimental results for the structure, formation, and stability of these self-trapped composite optical beams and also discuss the effects of anisotropy and of the nonlocality of the photorefractive nonlinearity on their properties. Additionally, we demonstrate, analytically and experimentally, that an array of the dipole-mode vector solitons can be generated as a result of the transverse instability of a quasi-one-dimensional two-hump soliton stripe in a saturable nonlinear optical medium.
49 citations
TL;DR: A simple phenomenological model for describing the conformational dynamics of biopolymers via the nonlinearity-induced buckling and collapse instability is proposed and its role in the folding dynamics of macromolecules is demonstrated through the three-dimensional numerical simulations of long semiflexible chains.
Abstract: We propose a simple phenomenological model for describing the conformational dynamics of biopolymers via the nonlinearity-induced buckling and collapse instability. We describe the buckling instability analytically, and then demonstrate its role in the folding dynamics of macromolecules through the three-dimensional numerical simulations of long semiflexible chains.
TL;DR: In this article, a conceptual approach to describe the properties of waveguides and circuits in photonic crystals is proposed, based on effective discrete equations that include long-range interaction effects.
Abstract: We suggest a novel conceptual approach to describing the properties of waveguides and circuits in photonic crystals, based on effective discrete equations that include long-range interaction effects. We demonstrate, through the example of sharp waveguide bends, that our approach is very effective and accurate for the study of bound states and transmission spectra of photonic-crystal circuits and disclose the importance of evanescent modes in these phenomena.
TL;DR: In this paper, the authors present an overview of the physics of self-written waveguides created in photosen-sitive optical materials, including the experimental observations and correspondingtheoretical models for describing the growth of both bright and dark selfwritten beams.
Abstract: Department of Applied Physics, Osaka University, Yamadaoka 2-1,Suita, Osaka 565-0871, JapanNanophotonics Laboratory, RIKEN, Wako, 351-0198, Japanhttp://lasie.ap.eng.osaka-u.ac.jp/Received 3 August 2002We present an overview of the physics of self-written waveguides created in photosen-sitive optical materials, including the experimental observations and the correspondingtheoretical models for describing the growth of both bright and dark self-written beams.We discuss in more details the properties of self-written waveguides created in photosen-sitive polymers, which have been discovered in the recent experimental and theoreticalstudies. The self-writing process is essentially a nonlinear phenomenon, since the tempo-ral dynamics depends on the optical exposure. Under appropriate conditions, permanentlarge changes in the refractive index are induced along the propagation direction of anoptical beam, so that optical channels, or \ laments", appear as waveguides becoming\frozen" in a photosensitive material. We describe the growth of individual lamentsas well as the interaction of several laments, also making a comparison between thephysics of self-written waveguides and the concept of spatial optical solitons in self-focusing nonlinear media.Keywords: Self-written waveguide; spatial soliton; nonlinear response; photosensitivematerial; photopolymers; self-action of light.
TL;DR: In this article, different types of ring-profile optical solitary wave and clusters of fundamental solitons propagating in isotropic nonlinear optical media are described and the stability of rotating soliton clusters due to vectorial interaction is demonstrated.
Abstract: We describe different types of ring-profile optical solitary wave and clusters of fundamental solitons propagating in isotropic nonlinear optical media. Such ringlike solitons carry a finite angular momentum and, depending on the value of the total momentum and structure, they either fragment quickly into several fundamental solitons that fly off the ring, or propagate stably for many diffraction lengths with rotating intensity and phase. Stabilization of the ring-profile optical beams and rotating soliton clusters due to vectorial interaction is also demonstrated.
TL;DR: A novel type of stable multicomponent dipole-mode solitons with intriguing swinging dynamics is described, which exhibit a symmetry-breaking instability, provided their total topological charge is nonzero.
Abstract: We study 2+1-dimensional multicomponent spatial vector solitons with a nontrivial topological structure of their constituents and demonstrate that these solitary waves exhibit a symmetry-breaking instability, provided their total topological charge is nonzero. We describe a novel type of stable multicomponent dipole-mode solitons with intriguing swinging dynamics.
Journal Article•
TL;DR: In this article, different types of ring-profile optical solitary wave and clusters of fundamental solitons propagating in isotropic nonlinear optical media are described and the stability of rotating soliton clusters due to vectorial interaction is demonstrated.
Abstract: We describe different types of ring-profile optical solitary wave and clusters of fundamental solitons propagating in isotropic nonlinear optical media. Such ringlike solitons carry a finite angular momentum and, depending on the value of the total momentum and structure, they either fragment quickly into several fundamental solitons that fly off the ring, or propagate stably for many diffraction lengths with rotating intensity and phase. Stabilization of the ring-profile optical beams and rotating soliton clusters due to vectorial interaction is also demonstrated.
TL;DR: A brief overview of the recent advances in the theoretical and experimental study of self-focusing and self-trapping of light is given in this paper, where different types of solitons and their stability are discussed.
Abstract: A brief overview of the recent advances in the theoretical and experimental study of self-focusing and self-trapping of light is given. Physical mechanisms of self-trapping and different types of self-trapped beams, spatial optical solitons, and their stability are discussed including solitons of non-Kerr media, self-trapped beams and their spiralling in photorefractive crystals, multi-hump solitons and solitonic gluons, discrete solitons in wave guide arrays, etc. A brief summary of the earlier and more recent experimental observations of spatial solitons, transverse instabilities, and soliton interactions is included as well.
Journal Article•
TL;DR: Kivshar and Stegeman as discussed by the authors presented a panoramic overview of the basic properties of optical solitons, emphasizing a variety of their characteristics and manifestations, and speculating on possible future developments and applications.
Abstract: 1047-6938/02/02/0059/5-$0015.00 © Optical Society of America One of the goals of modern nonlinear optics is the development of the ultimate fast, all-optical device in which light can be used to control light. The unique possibilities of reconfigurable circuits created in nonlinear bulk media without any fabricated optical waveguide can be achieved by employing the fundamental concept of light guiding light, based on the propagation of spatial optical solitons.1,2 Spatial solitons, or self-trapped, self-guided light beams that do not spread because of diffraction when they propagate in a nonlinear bulk medium, are considered information-carrying units, and the process of all-optical switching can be associated with the evolution of different types of spatial optical solitons and the interactions between them. Solitons are ubiquitous in nature: They occur whenever a wave travels in a medium that exhibits nonlinear behavior that YURI S. KIVSHAR and GEORGE I. STEGEMAN Spatial optical solitons may provide a powerful means for creating reconfigurable, all-optical circuits in which light is guided and controlled by light. We present a panoramic overview of the basic properties of optical solitons, emphasizing a variety of their characteristics and manifestations, and speculating on possible future developments and applications.
TL;DR: A novel type of second-order cascading by which the signal that is cross polarized to the pump can be split with an efficiency of more than 100%.
Abstract: We describe a novel type of second-order cascading by which the signal that is cross polarized to the pump can be split with an efficiency of more than 100%. The process requires the simultaneous phase matching of two second-order parametric interactions, whcih can easily be achieved with recently fabricated two-dimensional nonlinear photonic crystals.
TL;DR: In this paper, the structure and stability of vortices in hybrid atomic-molecular Bose-Einstein condensates are analyzed in the framework of a two-component Gross-Pitaevskii-type model that describes the stimulated Raman-induced photoassociation process.
Abstract: The structure and stability of vortices in hybrid atomic-molecular Bose-Einstein condensates is analysed in the framework of a two-component Gross-Pitaevskii-type model that describes the stimulated Raman-induced photoassociation process. New types of topological vortex states are predicted to exist in the coherently coupled two-component condensates even without a trap, and their nontrivial dynamics in the presence of losses is demonstrated.
TL;DR: In this paper, the existence and stability of multi-component spatial optical solitons in anisotropic nonlocal photorefractive media was studied and their stability was confirmed by an experimental observation.
TL;DR: In this article, the authors studied the breather collisions in a weakly discrete sine-Gordon equation and revealed a new mechanism of fractal soliton scattering in the dynamics of cold soliton gas.
Abstract: We study the breather collisions in a weakly discrete sine-Gordon equation and reveal a new mechanism of fractal soliton scattering. We demonstrate how this new mechanism manifests itself in the dynamics of cold soliton gas.
TL;DR: In this article, a book review of Massive WDM and TDM Soliton Transmission Systems: A ROSC Symposium, edited by Akira Hasagawa, summarizes proceedings from a symposium held 9-12 November 1999 in Kyoto, Japan.
Abstract: Yuri Kivshar, Australian National University, provides a book review of Massive WDM and TDM Soliton Transmission Systems: A ROSC Symposium, edited by Akira Hasagawa. The volume summarizes proceedings from a symposium held 9-12 November 1999 in Kyoto, Japan.
TL;DR: In this article, the possibility of strongly inelastic soliton collisions in a weakly discrete medium from the analysis of two-soliton solution to the nonlinear Schrodinger equation was predicted.
Abstract: We predict the possibility of strongly inelastic soliton collisions in a weakly discrete medium from the analysis of two-soliton solution to the nonlinear Schrodinger equation and confirm the prediction numerically. The effect turns out to be qualitatively independent on the particular type of perturbation. The conditions of mutual trapping of the colliding solitons are discussed as well.
01 Sep 2002
TL;DR: In this article, the authors analyze the beam propagation in modulated waveguide arrays, which consist of two types of alternating waveguides with different widths, and identify the presence of the Rowland ghost gap in the linear transmission spectrum.
Abstract: We analyze the beam propagation in modulated waveguide arrays, which consist of two types of alternating waveguides with different widths. Using effective discrete equations, we identify the presence of the so-called Rowland ghost gap in the linear transmission spectrum, and consider the effect of Kerr-type nonlinear self-action, describing two distinct classes of discrete solitons: (i) conventional discrete solitons, and (ii) discrete gap solitons. We demonstrate that the gap solitons can be efficiently generated by Gaussian input beams; both the soliton velocity and its propagation direction can be controlled by varying the input light intensity.
01 Jan 2002
TL;DR: In this paper, the authors provide an overview of the interaction properties of spatial optical solitons, such as their scattering properties, including a range of inelastic interactions, which are equivalent to those of deformable quasi-particles and are readily observed in experiments where underlying physical models are always nonintegrable.
Abstract: Publisher Summary This chapter provides an overview of the interaction properties of spatial optical solitons, such as their scattering properties, including a range of inelastic interactions. In the integrable systems, the soliton interaction is always elastic, and the only result of a collision in the nonlinear system, where the linear superposition principle does not hold, is the appearance of a soliton phase shift that accumulates during the strong overlap of the colliding solitons. The size of this phase shift depends on the initial parameters of the colliding solitons such as their velocities and amplitudes. In the case of the so-called multicomponent systems, where the input beam can be decomposed into a set of incoherently coupled components, the phase shift differs between components and this can result in the so-called shape transformation of the beam during a collision. In nonintegrable systems, the solitons can exchange energy, fuse, or even split into multiple components. Such inelastic interactions are equivalent to those of deformable quasi-particles and are readily observed in experiments where underlying physical models are always nonintegrable.
01 Sep 2002
TL;DR: In this paper, the authors derived effective discrete equations with long-range interaction which accurately describe light transmission in photonic crystal waveguides with embedded nonlinear defects and demonstrate the possibility of a bistable (all-optical switcher) and unidirectional (optical diode) transmission.
Abstract: We derive effective discrete equations with long-range interaction which accurately describe light transmission in photonic crystal waveguides with embedded nonlinear defects and demonstrate the possibility of a bistable (all-optical switcher) and unidirectional (optical diode) transmission.
02 Sep 2002
TL;DR: In this paper, the authors suggest a novel concept of diffraction management in waveguide arrays and predict the existence of discrete gap solitons that possess the properties of both conventional discrete and Bragg grating solITons.
Abstract: We suggest a novel concept of diffraction management in waveguide arrays and predict the existence of discrete gap solitons that possess the properties of both conventional discrete and Bragg grating solitons. We demonstrate that both the soliton velocity and propagation direction can be controlled by varying the input light intensity.
01 Sep 2002
TL;DR: In this article, a family of three-component dipole-mode spatial solitons for nonlinear saturable (isotropic and anisotropic photorefractive) bulk media is studied.
Abstract: We study, theoretically and experimentally, multicomponent spatial solitons in nonlinear saturable (isotropic and anisotropic photorefractive) bulk media We find numerically a family of the three-component dipole-mode solitons and demonstrate their stability in a wide range of the input parameters We also observe the formation and stability of these spatial solitons in experiment with photorefractive strontium barium niobate (SBN) crystals