Hexagon patterns in optical bistability

The mean-field model of optical bistability in a ring cavity is extended to include diffraction in two transverse dimensions. Nonlinear analysis in the neighborhood of the instability of the homogeneous solution indicates the formation of stable hexagonal patterns, and this is confirmed by numerical simulation, with reasonable quantitative agreement. Simulations with higher excitation show defect structures and complex dynamical patterns

A generic travelling wave solution in dissipative laser cavity

A large family of cosh-Gaussian travelling wave solution of a complex Ginzburg–Landau equation (CGLE), that describes dissipative semiconductor laser cavity is derived. Using perturbation method, the stability region is identified. Bifurcation analysis is done by smoothly varying the cavity loss coefficient to provide insight of the system dynamics. He’s variational method is adopted to obtain the standard sech-type and the notso-explored but promising cosh-Gaussian type, travelling wave solutions. For a given set of system parameters, only one sech solution is obtained, whereas several distinct solution points are derived for cosh-Gaussian case. These solutions yield a wide variety of travelling wave profiles, namely Gaussian, near-sech, flat-top and a cosh-Gaussianwith variable central dip. A split-step Fourier method and pseudospectral method have been used for direct numerical solution of the CGLE and travelling wave profiles identical to the analytical profiles have been obtained. We also identified the parametric zone that promises an extremely large family of cosh-Gaussian travelling wave solutions with tunable shape. This suggests that the cosh-Gaussian profile is quite generic and would be helpful for further theoretical as well as experimental investigation on pattern formation, pulse dynamics andlocalization in semiconductor laser cavity

Vector cavity solitons in broad area Vertical-Cavity Surface-Emitting lasers

We report the experimental observation of two-dimensional vector cavity solitons in a Vertical-Cavity Surface-Emitting Laser (VCSEL) under linearly polarized optical injection when varying optical injection linear polarization direction. The polarization of the cavity soliton is not the one of the optical injection as it acquires a distinct ellipticity. These experimental results are qualitatively reproduced by the spin-flip VCSEL model. Our findings open the road to polarization multiplexing when using cavity solitons in broad-area lasers as pixels in information technology

Spontaneous and induced motion of optical patterns

The universality of two mechanisms of motion of patterns in nonlinear optics is demonstrated. In the first one, two-dimensional disordered patterns are shown to scroll with constant velocity after transients are discarded. In the second case, pattern motion is induced by background modulations. Spatially periodic patterns lock to maxima or minima of the underlying modulation depending on its wavevector

Temporal cavity solitons in one-dimensional Kerr media as bits in an all-optical buffer

Temporal cavity solitons are packets of light persisting in a continuously driven nonlinear resonator. They are robust attracting states, readily excited through a phase-insensitive and wavelength-insensitive process. As such, they constitute an ideal support for bits in an optical buffer that would seamlessly combine three critical telecommunication functions, namely all-optical storage, all-optical reshaping and wavelength conversion. Here, with standard silica optical fibres, we report the first experimental observation of temporal cavity solitons. The cavity solitons are 4 ps long and are used to demonstrate storage of a data stream for more than a second. We also observe interactions of close cavity solitons, revealing for our set-up a potential capacity of up to 45,000 bits at 25Gbit s-1. More fundamentally, cavity solitons are localized dissipative structures. Therefore, given that silica exhibits a pure instantaneous Kerr nonlinearity, our experiment constitutes one of the simplest examples of self-organization phenomena in nonlinear optics. © 2010 Macmillan Publishers Limited. All rights reserved.SCOPUS: ar.jinfo:eu-repo/semantics/publishe