Separate Spatial Soliton Pair Research Articles

Tunable evolutions of bright beams in a separate spatial soliton pair due to the crystal temperature

We numerically investigate the temperature characteristics of the bright soliton and a Gaussian beam in a photorefractive crystal circuit, in which two photorefractive crystals are connected with an external voltage source. The results indicate that the dynamical evolution of the bright soliton and the Gaussian beam formed in one crystal depend strongly on the temperature of the other crystal, in which the dark soliton is formed. For the bright soliton, the full width at half maximum (FWHM) of the soliton increases and the center deflection decreases with the increase of the dark soliton crystal temperature. The Gaussian beam shows the similar evolution behaviors and experiences periodic compression and expansion during propagation. The deviation between the bright soliton and the Gaussian beam, however, becomes obvious as the increase of the temperature of the dark soliton crystal. A Gaussian beam that is mismatched with the bright soliton supported by the crystal could evolve into a bright solitary wave by tuning the temperature of the dark soliton crystal properly.

The evolution and deflection characteristics of Gaussian beam in photovoltaic photorefractive crystal circuit with dark soliton intensity effect

In this paper, based on the theory of the separate spatial soliton pair, the dynamical evolution and deflection characteristics of Gaussian beam in a biased series photovoltaic photorefractive crystals circuit are investigated numerically by taking into account the variation of the dark soliton intensity. The results show that changing the dark soliton intensity in one crystal can modulate the dynamical evolution and deflection of Gaussian beam in the other crystal. When the change of the dark soliton intensity is large enough, the matched Gaussian beam can not evolve into a solitary wave. By adjusting the dark soliton intensity a mismatched Gaussian beam can evolve into a stable bright soliton. We give some examples in this paper.

Separate spatial soliton pairs in a biased series photorefractive crystal circuit with both the linear and quadratic electro-optic effects

We investigate the separate spatial soliton pair supported by both the linear and quadratic electro-optic effects. The numerical solutions of the bright–bright, dark–dark and bright–dark separate spatial soliton pairs are deduced from the coupling equations. The intensity profiles, coupling effects and dynamical evolutions of three types of separate spatial soliton pairs are analysed by numerical method. The two solitons in bright–bright separate spatial soliton pair can affect each other only by adjusting the background beam intensity. In dark–dark soliton pair, the two solitons can affect each other by adjusting the soliton beam intensity besides the background beam. And in bright–dark soliton pair, the bright soliton can affect the dark soliton only by the background beam intensity but the dark soliton can affect the bright soliton by both the background beam and soliton beam intensity.

Effect of the dark soliton crystal temperature on the dynamical evolution of Gaussian beam in a biased series photorefractive crystal circuit

Based on the theory of separate spatial soliton pair and the evolution of Gaussian beam in a photorefractive crystal, we investigate the effect of the dark soliton crystal temperature on the dynamical evolution of Gaussian beam in a biased series circuit consisting of two non-photovoltaic photorefractive crystals numerically. Results show that adjusting the temperature of the dark soliton crystal can modulate the dynamical evolution of Gaussian beam in the other crystal. For example, the matched Gaussian beam cannot evolve into a solitary wave when the change of the dark soliton crystal temperature is large enough and a mismatched Gaussian beam can evolve into a stable bright soliton by adjusting the temperature of the dark soliton crystal. Some examples are given in this paper.

Coupling effects of grey–grey separate spatial screening soliton pairs

The existence and coupling effects of grey–grey separate spatial soliton pairs in a biased series non-photovoltaic photorefractive crystal circuit are investigated in this paper. The numerical solution of grey–grey soliton pairs is derived. The coupling effects between two grey solitons resulting from the input optical intensity and crystal temperature are analyzed numerically. The results show that when the input optical intensity of one crystal changes, two grey solitons in a soliton pair will all change; that is, two grey solitons can affect each other by the light-induced current that flows from one crystal to another. When the temperature of one crystal increases, the intensity width of the grey soliton in this crystal first decreases and then increases. Simultaneously, the intensity width of another grey soliton increases monotonically.

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.

Grey–grey separate spatial soliton pairs in a biased series two-photon centrosymmetric photorefractive crystals circuit

Grey–grey separate spatial soliton pairs are predicted in a biased series circuit consisting of two centrosymmetric photorefractive (PR) crystals with the two-photon PR effect. The numerical results show that two grey solitons in a soliton pair can affect each other by the light-induced current. The effects of the intensity of solitary waves and gating lights on the normalized profiles and the dynamical evolutions of solitons are discussed.

Grey–grey separate spatial soliton pairs in a biased series photorefractive polymer circuit

Grey–grey separate spatial soliton pairs are predicted in a biased series circuit consisting of two guest-host photorefractive polymers. The numerical results show that two grey solitons in a soliton pair can affect each other by the light-induced current.

Separate spatial soliton pairs in an unbiased series two-photon photorefractive crystal circuit

Dark (bright) steady-state spatial solitons are predicted in one dimension for a series circuit consisting of two two-photon photorefractive crystals of which at least one must be photovoltaic. Each crystal can support a spatial soliton. The two solitons are known collectively as separate spatial soliton pairs with three types: dark–dark, bright–dark and bright–bright. In the limit in which the optical wave has a spatial extent much less than the width of the crystal, the dark soliton can affect the other soliton by light-induced current, but the bright soliton cannot affect the other soliton in the soliton pair.

Separate spatial Holographic-Hamiltonian soliton pairs and solitons interaction in an unbiased series photorefractive crystal circuit

This paper presents calculations for an idea in photorefractive spatial soliton, namely, a dissipative holographic soliton and a Hamiltonian soliton in one dimension form in an unbiased series photorefractive crystal circuit consisting of two photorefractive crystals of which at least one must be photovoltaic. The two solitons are known collectively as a separate Holographic-Hamiltonian spatial soliton pair and there are two types: dark-dark and bright-dark if only one crystal of the circuit is photovoltaic. The numerical results show that the Hamiltonian soliton in a soliton pair can affect the holographic one by the light-induced current whereas the effect of the holographic soliton on the Hamiltonian soliton is too weak to be ignored, i.e., the holographic soliton cannot affect the Hamiltonian one.

Self-deflection of a bright soliton in a separate bright-dark spatial soliton pair based on a higher-order space charge field

The self-deflection of a bright solitary beam can be controlled by a dark solitary beam via a parametric coupling effect between the bright and dark solitary beams in a separate bright-dark spatial soliton pair supported by an unbiased series photorefractive crystal circuit. The spatial shift of the bright solitary beam centre as a function of the input intensity of the dark solitary beam () is investigated by taking into account the higher-order space charge field in the dynamics of the bright solitary beam via both numerical and perturbation methods under steady-state conditions. The deflection amount (Δs0), defined as the value of the spatial shift at the output surface of the crystal, is a monotonic and nonlinear function of . When is weak or strong enough, Δs0 is, in fact, unchanged with , whereas Δs0 increases or decreases monotonically with in a middle range of . The corresponding variation range (δs) depends strongly on the value of the input intensity of the bright solitary beam (r). There are some peak and valley values in the curve of δs versus r under some conditions. When increases, the bright solitary beam can scan toward both the direction same as and opposite to the crystal's c-axis. Whether the direction is the same as or opposite to the c-axis depends on the parameter values and configuration of the crystal circuit, as well as the value of r. Some potential applications are discussed.

Separate spatial soliton pairs and solitons interaction in an unbiased series photorefractive crystal circuit

Dark (bright) steady-state spatial solitons are predicted in one dimension for a series circuit consisting of two photorefractive crystals of which at least one must be photovoltaic. Each crystal can support a spatial soliton. The two solitons are known collectively as a separate spatial soliton pair with three types: bright–bright, bright–dark and dark–dark. In the limit in which the spatial extent of the optical wave is much less than the width of the crystal, the dark soliton can affect the other soliton whereas the bright soliton cannot affect the other soliton in the soliton pair.

Modulation on dynamical evolution of Gaussian beam in an unbiased serial photorefractive crystal circuit*

Based on the theory of one\|dimensional separate spatial soliton pair formed in an unbiased serial photorefractive(PR) crystal circuit consis-ting of two PR crystals connected by electrodes, the mutual dependences of the two solitons are investigated. When a dark soliton beam and a Gaussian beam are incident on the two PR crystals, respectively, the effects of changing the peak intensity of the dark soliton on the propagating property of the Gaussian beam are discussed by numerical calculations. The result shows that the dynamical evolution of Gaussian beam in one crystal can be modulated by changing the intensity of the dark soliton in the other in the circuit. By this way one can determine whether the Gaussian beam could evolve into a solitary wave or ont.