Light-bullet routing and control with planar waveguide arrays

Mode-locking in quadratically nonlinear waveguide arrays

A two-dimensional theoretical model is constructed to describe optical mode-locking (ML) in quadratically nonlinear waveguide arrays (QWGAs). Steady-state solutions of the considered model are obtained by a modified pseudo-spectral renormalization algorithm, and the mode-locking dynamics of the model are investigated through direct simulation of the nonlinear evolution and a linear stability analysis of the solutions. It is shown that stable mode-locking of elliptic steady-state solutions in quadratically nonlinear waveguide arrays are possible for a wide range of parameters, suggesting that quadratically nonlinear materials are well suited for producing stable mode-locked states for a wide range of applications.

Spatiotemporal mode locking in quadratic nonlinear media

A theoretical model is developed to characterize spatiotemporal mode locking (ML) in quadratic nonlinear media. The model is based on the two-dimensional nonlinear Schrödinger equation with coupling to a mean term (NLSM) and constructed as an extension of the master mode-locking model. It is numerically demonstrated that there exists steady-state soliton solutions of the ML-NLSM model that are astigmatic in nature. A full stability analysis and bifurcation study is performed for the ML-NLSM model, and it is manifest that spatiotemporal ML of the astigmatic steady-state solutions is possible in quadratic nonlinear media.

Rotation-managed dissipative solitons

We show that when spatially localized gain landscape performs accelerated motion in the transverse plane, i.e., when it rotates or oscillates around the light propagation axis, the effective gain experienced by the light beam considerably reduces with an increase of the amplitude of oscillations or frequency of rotation of the localized gain. In the presence of uniform background losses and defocusing nonlinearity, such gain landscapes may support dynamically oscillating gain-managed solitons, but if the amplitude of oscillations or the frequency of rotation of the localized gain exceeds a threshold, stable attractors disappear and any input beam decays.

Solitons supported by localized parametric gain

We address the existence and properties of one-dimensional solitons maintained by localized parametric gain in focusing and defocusing lossy nonlinear media. Localized parametric gain supports both fundamental and multipole solitons. We found that the family of fundamental solitons is partly stable in focusing nonlinear medium, and completely stable in defocusing medium, while all higher-order solitons are unstable. In addition to numerical results, the existence threshold for the solitons and a particular stable exact solution are obtained in an exact analytical form.

Soliton generation by counteracting gain-guiding and self-bending

We introduce a concept for stable spatial soliton formation, mediated by the competition between self-bending induced by a strongly asymmetric nonlocal nonlinearity and spatially localized gain superimposed on a wide pedestal with linear losses. When acting separately both effects seriously prevent stable localization of light, but under suitable conditions they counteract each other, forming robust soliton states that are attractors for a wide range of material and input light conditions.

Generation of spatial solitons by a localized active cluster

The formation, stability, and dynamics of solitons are considered in an optical system with focusing nonlinearity and active clusters. It is shown that stochastic generation of solitons is possible in such a system provided the cluster properties are properly designed.

Solitons in a medium with linear dissipation and localized gain

We present a variety of dissipative solitons and breathing modes in a medium with localized gain and homogeneous linear dissipation. The system possesses a number of unusual properties, like exponentially localized modes in both focusing and defocusing media, existence of modes in focusing media at negative propagation constant values, simultaneous existence of stable symmetric and antisymmetric localized modes when the gain landscape possesses two local maxima, as well as the existence of stable breathing solutions.

Two-dimensional dissipative solitons supported by localized gain

We show that the balance between localized gain and nonlinear cubic dissipation in the two-dimensional nonlinear Schrödinger equation allows for the existence of stable localized modes that we identify as solitons. Such modes exist only when the gain is strong enough and the energy flow exceeds certain threshold value. Above the critical value of the gain, symmetry breaking occurs and asymmetric dissipative solitons emerge.