Bright-dark Soliton Pairs Research Articles

Bright-dark soliton pairs in a self-mode locking fiber laser

We have experimentally observed bright-dark soliton pairs in an erbium-doped fiber ring laser for the first time. This approach is different from the vector dark domain wall solitons which separate the two orthogonal linear polarization eigenstates of the laser emission. In our laser, the bright-dark soliton pairs can co-exist in any one polarization state. Numerical simulations based on the coupled complex Ginzburg-Landau equations have confirmed the experimental results.

The temperature characteristics of unbiased separate spatial soliton pairs due to two-photon photorefractive effect

We investigate theoretically the temperature effects on the intensity profile and spatial evolution of separate spatial soliton pairs formed in a serial two-photon photovoltaic photorefractive crystal circuit. Our numerical results show that, for a stable bright–dark soliton pair, when the temperature of the dark soliton crystal changes, the intensity profiles of the dark and the bright soliton will all change. When the temperature of the bright soliton crystal changes, only change the intensity profiles of the bright soliton will. For a bright–bright soliton pairs, the intensity profiles of the soliton determined only by the parameters of the corresponding crystal, whereas the intensity profiles of the soliton determined by the parameters of two crystals for the dark–dark soliton pairs. Finally, we discuss the temperature of dark solitons effects on the dynamical evolution of bright–dark soliton pairs.

All-Optical Nanoscale Microring Device and System Design for Nano Communication

In this paper, we have shown that the two components (TE and TM waves) of polarized light are manipulated by using the orthogonal soliton pair within a PANDA ring resonator known as a dark-bright soliton pair. In operation, the orthogonal soliton sets can be generated by using the system. The optical field is fed into the ring resonator system, which is controlled by an optical switch by using a single microring. To form the initial spin states, the magnetic field is induced by an aluminum plate (Al) coupled on AlGaAs waveguides for optoelectronic spin-up and - down states. The optoelectronic spin is formed by using the TE and TM wave components. In this manipulation, the electromagnetic radiation is formed by using the orthogonal soliton pulses. In fact, they are photons, which behave like elementary particles. Hence, the spin axis of photon is always parallel to its direction of motion. Many orthogonal sets are also available and existed, in which the spin conservation of many particles is maintained for large scale system use. Therefore, for future applications, the use for high performance storage, low power magnetic logic, quantum logic, quantum gate, nano antenna, nano radio, and applications of spintronic sensing can be realized based on realistic device parameters.

Stability of incoherently coupled bright–dark spatial soliton pairs in biased two-photon photovoltaic photorefractive crystals

This paper investigated numerically the stability of bright–dark soliton pairs in biased two-photon photovoltaic photorefractive crystals. Our analysis indicates that these soliton pairs exist irrespective of the polarity of photovoltaic field and external bias field and they are stable only in the particular range of negative polarity. That is to say, the modulational instability emerges for the positive polarity. In range of negative polarity, there exist a characteristic value of photovoltaic field and external bias field. When the values are less than the characteristic value, these bright–dark soliton pairs are stable. If the values are large than the characteristic value, the modulational instability will still emerge.

Separate spatial soliton pairs in biased series photorefractive polymer circuit

This paper presents calculations based on the idea of photorefractive polymer spatial solitons, namely, screening solitons being formed in a biased series photorefractive polymer circuit consisting of two photorefractive polymer connected electronically by electrode leads in a chain with a voltage source. A system of two coupled equations is derived under appropriate conditions for two-beam propagation in the series photorefractive polymer circuit. The existence of dark-dark, bright-dark and bright-bright photorefractive polymer soliton pairs in such a circuit is proved. In the limit in which the optical wave has a spatial extent much less than the width of the photorefractive polymer, the two solitons in dark-dark soliton pairs can affect each other’s spatial profiles and the dynamical evolution by the light-induced current. For a bright-dark soliton pair, the dark soliton can affect the other soliton by light-induced current, but the bright soliton cannot. The two solitons in bright-bright soliton pairs cannot affect each other.

无偏压光伏晶体中的非相干耦合亮暗孤子对及其传输特性

无偏压光伏晶体中的非相干耦合亮暗孤子对及其传输特性

Dark–bright discrete solitons: A numerical study of existence, stability and dynamics

In the present work, we numerically explore the existence and stability properties of different types of configurations of dark–bright solitons, dark–bright soliton pairs and pairs of dark–bright and dark solitons in discrete settings, starting from the anti-continuum limit. We find that while single discrete dark–bright solitons have similar stability properties to discrete dark solitons, their pairs may only be stable if the bright components are in phase and are always unstable if the bright components are out of phase. Pairs of dark–bright solitons with dark ones have similar stability properties as individual dark or dark–bright ones. Lastly, we consider collisions between dark–bright solitons and between a dark–bright one and a dark one. Especially in the latter and in the regime where the underlying lattice structure matters, we find a wide range of potential dynamical outcomes depending on the initial soliton speed.

中心对称光折变介质中双光子非相干耦合屏蔽孤子对

The coupling of two mutually incoherent optical beams with the same polarization and wavelength in two-photon cen-trosymmetric photorefractive crystals is studied. The result shows that incoherently coupled dark-dark, bright-bright and bright-dark screening soliton pairs in centrosymmetric photorefractive crystals are possible due to two-photon photorefractive effect.

DARK SOLITON BEHAVIORS WITHIN THE NONLINEAR MICRO AND NANORING RESONATORS AND APPLICATIONS

We propose some fascinating results regarding dark soliton pulse propagation within the nonlinear micro and nano waveguides. The system consists of nonlinear micro and nanoring resonators whereby the dark soliton is input into the system and travels within the waveguide. A continuous dark soliton pulse is sliced into smaller pulses by the nonlinear efiect which is known as chaos. The nonlinear behaviors such as chaos, bistability and bifurcation are analyzed and discussed. The broad area of applications such as dark-bright soliton conversion and power ampliflcation, binary code generation by the dark-bright soliton pair, dark soliton trapping and millimeter wave generation are proposed and discussed. The biggest advantage is that, where security is the most important consideration, power ampliflcation can be used to perform the long distance link.

Various kinds of spatial solitons associated with photoisomerization

It is predicted that the fundamental spatial solitons, namely bright, dark, and gray solitons associated with photoisomerization, can be formed stably except for antidark solitons. The soliton solutions and the relative properties of these solitons are given in detail. Incoherently coupled bright-dark soliton pairs are also investigated. Both the cases indicate that although the formation of a spontaneous bright soliton based on photoisomerization is impossible, it is, however, possible to form a bright soliton with the joining of a background light or the coupling of another dark soliton. The results provide possible methods of controlling a light with another light.

Coupled Bright-Dark Soliton Pairs in Polymeric Photorefractive Materials

We have shown that under appropriate steady state conditions, two-component coupled bright-dark soliton pairs can be established in biased polymeric photorefractive materials. These bright-dark soliton pairs are possible if both carrier beams possess same wavelength and polarization. They are mutually incoherent and stable against small perturbation.

The effects of temperature on the stability and evolution of separate photovoltaic bright–dark spatial soliton pair

The temperature effects on the evolution and stability of a separate photovoltaic bright–dark soliton pair formed in a serial photovoltaic photorefractive crystal circuit have been investigated. Our numerical results show that adjusting each crystal temperature can affect the dynamical evolution of the soliton formed in the other crystal. For a stable bright–dark soliton pair originally formed in a crystal circuit at given temperatures, when one crystal temperature changes, the soliton supported by the other crystal will evolve into another stable soliton if the temperature change is quite small, whereas it will become unstable and experience larger cycles of compression or break up into beam filaments if the temperature difference is big enough. The bright soliton and dark solitons have their own stable temperature regime.

Temperature effects of dark solitons on the self-deflection of bright solitons in a separate bright-dark soliton pair

Based on the theory of one-dimensional separate soliton pairs formed in a serial photorefractive crystal circuit, we investigated the temperature effects of the dark soliton on the self-deflection of the bright soliton in a bright-dark soliton pair. The numerical results obtained by solving the nonlinear propagation equation showed that the bright soliton moves on a parabolic trajectory in the crystal and its spatial shift changed with the temperature of the dark soliton. The higher the temperature of the dark soliton was, the smaller the spatial shift of the bright soliton was. The self-bending process was further studied by the perturbation technique, and the results were found to be in good agreement with that obtained by the numerical method.

Effect of the dark soliton crystal temperature on the deflection of the bright soliton in a separate bright–dark screening soliton pair

We investigate theoretically the dark soliton crystal temperature effect on the deflection of the bright one in a bright–dark soliton pair which is formed in a serial non-photovoltaic photorefractive crystal circuit. Our numerical results show that the spatial shift of the bright soliton changes with the temperature of the dark one crystal and varying the temperature of the dark soliton crystal can influence the deflection strongly. The temperature dependence of the deflection process is further studied by perturbation technique and the results are found to be good agreement with that obtained by numerical method. Relevant examples are provided.

Dark-bright soliton pairs in nonlocal nonlinear media

We study the formation of dark-bright vector soliton pairs in nonlocal Kerr-type nonlinear medium. We show, by analytical analysis and direct numerical calculation, that in addition to stabilize of vector soliton pairs nonlocal nonlinearity also helps to reduce the threshold power for forming a guided bright soliton. With help of the nonlocality, it is expected that the observation of dark-bright vector soliton pairs in experiments becomes more workable.

Incoherently coupled spatial soliton pairs in two-photon photorefractive media

The coupling of two mutually incoherent optical beams with the same polarization and wavelength in two-photon photorefractive crystals is studied. It is shown that incoherently coupled dark-dark, bright-bright, and bright-dark soliton pairs are possible due to two-photon photorefractive effect.

Effects of temperature on the stability of separate screening bright–dark spatial soliton pair

We investigate theoretically the temperature effects on the evolution and stability of a separate screening bright–dark soliton pair formed in a serial non-photovoltaic photorefractive crystal circuit. Our numerical results show that, for a stable bright–dark soliton pair originally formed in a crystal circuit at given temperatures, when one crystal temperature changes, the soliton supported by the other crystal will evolve into another stable soliton if the temperature change is quite small, whereas it will become unstable and experience larger cycles of compression or break up into beam filaments if the temperature difference is big enough. The dark soliton is more sensitive to the temperature change than the bright one.

Effects of dark soliton crystal temperature on the self-deflection of bright soliton in a biased serial photovoltaic photorefractive crystal circuit

Based on the theory of one-dimensional separate soliton pairs formed in a serial photovoltaic photorefractive crystal circuit, the effects of the dark soliton crystal temperature on the self-deflection of the bright one in a bright–dark soliton pair are investigated. The numerical results indicate that the spatial shift of the bright soliton can experience obvious increase in their self-deflection with the increase of the temperature of the dark soliton. The self-bending process is further studied using perturbation techniques and the results are found to be good agreement with that obtained by numerical method.

Vector solitons with an embedded domain wall

We present a class of soliton solutions to a system of two coupled nonlinear Schrödinger equations, with an intrinsic domain wall (DW) which separates regions occupied by two different fields. The model describes a binary mixture of two Bose-Einstein condensates (BECs) with interspecies repulsion. For the attractive or repulsive interactions inside each species, we find solutions which are bright or dark solitons in each component, while for the opposite signs of the intraspecies interaction, a bright-dark soliton pair is found (each time, with the intrinsic DW). These solutions can arise in the context of discrete lattices, and most of them can be supported in continuum settings by an external parabolic trap. The stability of the solitons with intrinsic DWs is examined, and the evolution of unstable ones is analyzed. We also briefly discuss the possibility of generating such families of solutions in the presence of linear coupling between the components, and an application of the model to bimodal light propagation in nonlinear optics.

Combined solitary-wave solution for coupled higher-order nonlinear Schrödinger equations

Coupled nonlinear Schrödinger equations model several interesting physical phenomena. We used a trigonometric function transform method based on a homogeneous balance to solve the coupled higher-order nonlinear Schrödinger equations. We obtained four pairs of exact solitary-wave solutions including a dark and a bright-soliton pair, a bright- and a dark-soliton pair, a bright- and a bright-soliton pair, and the last pair, a combined bright–dark-soliton pair.