The photoconductor behaves like a variable resistance, which decreases for increasing illumination. From the second term in Eq. Such numerically obtained k, ω -plot is shown in Fig. The frame on the left is a magnified section of the initial propagation of the beam. A global phase gradient which induces a continuous and smooth drift motion of feedback solitons, can be created if the feedback system is detuned by slightly misaligning either a mirror or one of the lenses.
Zirbel, Physica D, 137, 353-378 2000. The one qualitative difference, beyond the presence of time-dependence, between binary fluid convection and a model equation such as the Swift-Hohenberg equation is the observed difference in the widths of the snaking regions for odd and even par- 6 Convectons 123 0. However, it is related to high non-linear behavior, and near to the weakly non-linear regime the destabilization process behaves as our perturbation method predicts. This book should appeal to all physicists, mathematicians and electrical engineers interested in localization in far-from-equilibrium systems. By further increasing the aperture to 1. The geotechnical risks in the city of Napoli and their mitigation A.
Knobloch, Nonlinearity 21, T45 2008. For this purpose, a hexagonal parameter gradient was chosen as a static background parameter on which drifted solitons will be addressed. Karpierz and Gaetano Assanto Figure 1. This counter-intuitive phenomenon is the result of period-halving bifurcations leading to order periodic explosions , followed by period-doubling bifurcations leading to chaos chaotic explosions. The guiding of dissipative solitons by one- and two-dimensional parameter modulations is demonstrated. Knobloch, Chaos 17, 037102 2007.
Thus, one can use the near-identity transformation to convert our system into one with the lowest order interaction Hamiltonian to be of degree six. We present a simple reaction-diffusion model for two variables. In fluids dissipation, whether through viscosity or thermal diffusion, is generally of great importance. Residori where Iw is the feedback intensity arriving onto the photoconductor and α is a phenomenological parameter summarizing, in the linear approximation, the response of the photoconductor. To find a nontrivial answer we need to obtain a first order addition Jk12345 1 to Jk12345. Using a prototype Swift-Hohenberg equation for the order parameter we study the localization mechanism for hexagons surrounded by a uniform phase. The negative slope branches of both solutions are unstable.
We study stationary, localized solutions in the complex subcritical Ginzburg-Landau equation in the region where there exists coexistence of homogeneous attractors. Preface Sponsors Cultural heritage and geotechnical engineering: An introduction C. As optical turbulence is our ultimate goal, we use light that is partially spatially incoherent. There are also no five-wave resonances because the original terms in the Hamiltonian are of the even orders. This balance, combined with that of gain and loss, allows the wave to maintain for long times a robust localized shape in space. These results could have significant ramifications for optical information processing. Experimentally, during the last years localized patterns or isolated states have been observed in many different fields.
A self-trapped light beam propagates in the thin layer where the refractive index is the largest close to nk. Our study demonstrates how the unique particle-like characteristics of cavity solitons can be leveraged to achieve unprecedented control over light. At this purpose, the intensity of the input beam is modulated with a patterned intensity mask, and in order to impose an initial condition close to the random phase approximation required by the theory, we have 4 Optical Wave Turbulence and Wave Condensation in a Nonlinear Optical Experiment 81 randomize the phases by a phase modulator. Its success is partly due to possible applications to all-optical information processing. The two observations of Fig. As previously explained, in our laser system bistability is achieved by biasing L2 below its transparency value and thus operating it as a saturable absorber. Physics Reports volume 416, issue 5-6, p.
Explicitly accounting for the principal value and pole in Eq. An illustration is shown in figures 11. These structures experience also a pinning force engendered by the attractive nature of the defect. Square, stripe, hexagonal and spiral patterns can emerge, depending on the oscillation frequency and amplitude of the forcing, including coherent states such as localized standing waves or oscillons. Express 12, 6524—6529 2004 A. Even though Localized States in Physics can be found in such different domains as hydrodynamics, optics, granular matter, reaction-diffusion systems, neural networks, plasmas, Bose-Einstein condensates etc.
B 24, 2314—2320 2007 A. The track positions of the soliton are marked as a o. Lancellotta The Leaning Tower of Pisa J. Consequently, the value reached by the field intensity at the end of injection is smaller and the population variables D and d remain sufficiently far from zero. A 283, 349 2001 8.
In the case of spatial incoherent excitations, e. Dissipative solitons show a variety of behaviors not exhibited by their conservative counterparts. Trehalose in Solution and Its Interaction with Water and Biological Structures. Haken Synergetics Springer, Berlin, 1983. When increasing the input intensity, more solitary structures arise and coexist in the transverse plane of the wave.
E 72, 045201 R , 2005. Technically, the plasma formula 2. As indicated above, the appearance of lower polygonal symmetries is ruled not only by the size of the imposed aperture, but also by the input intensity. Kalogeras The role of geotechnical conditions in the foundation, expansion and preservation of the ancient town of Orvieto Italy P. Duplication of this publication or parts thereof is permitted only under the provisions of the German Copyright Law of September 9, 1965, in its current version, and permission for use must always be obtained from Springer. Because the birefringence axis rotates across 12 Miroslaw A.