29 research outputs found
Relativistic regimes for dispersive shock-waves in non-paraxial nonlinear optics
We investigate the effect of non-paraxiality in the dynamics of dispersive
shock waves in the defocusing nonlinear Schroedinger equation. We show that the
problem can be described in terms of a relativistic particle moving in a
potential. Lowest order corrections enhance the wave-breaking and impose a
limit to the highest achievable spectrum in an amount experimentally testable.Comment: 6 pages, 4 figure
Soliton electro-optic effects in paraelectrics
The combination of charge separation induced by the formation of a single
photorefractive screening soliton and an applied external bias field in a
paraelectric is shown to lead to a family of useful electro-optic guiding
patterns and properties.Comment: 3 pages, 5 figure
Subwavelength optical spatial solitons and three-dimensional localization in disordered ferroelectrics: towards metamaterials of nonlinear origin
We predict the existence of a novel class of multidimensional light
localizations in out-of-equilibrium ferroelectric crystals. In two dimensions,
the non-diffracting beams form at arbitrary low power level and propagate even
when their width is well below the optical wavelength. In three dimensions, a
novel form of subwavelength light bullets is found. The effects emerge when
compositionally disordered crystals are brought to their metastable glassy
state, and can have a profound impact on super-resolved imaging and ultra-dense
optical storage, while resembling many features of the so-called metamaterials,
as the suppression of evanescent waves.Comment: 4 pages, 3 figure
Stable oscillating nonlinear beams in square-wave-biased-photorefractives
We demonstrate experimentally that in a centrosymmetric paraelectric
non-stationary boundary conditions can dynamically halt the intrinsic
instability of quasi-steady-state photorefractive self-trapping, driving beam
evolution into a stable oscillating two-soliton-state configuration.Comment: 3 pages, 4 figs, revtex os
Programming scale-free optics in disordered ferroelectrics
Using the history-dependence of a dipolar glass hosted in a
compositionally-disordered lithium-enriched potassium-tantalate-niobate
(KTN:Li) crystal, we demonstrate scale-free optical propagation at tunable
temperatures. The operating equilibration temperature is determined by previous
crystal spiralling in the temperature/cooling-rate phase-space
Anisotropic charge displacement supporting isolated photorefractive optical needles
The strong asymmetry in charge distribution supporting a single
non-interacting spatial needle soliton in a paraelectric photorefractive is
directly observed by means of electroholographic readout. Whereas in trapping
conditions a quasi-circular wave is supported, the underlying double-dipolar
structure can be made to support two distinct propagation modes.Comment: 3 pages, 3 figure
Reduced statistical fluctuations of the position of an object partitioning in two its environment
Through hard‐disk simulations and theoretical considerations on the movement of an object that partitions a microtubule filled with small particles, we find that the vibrations typical of thermal equilibrium are reached after a time that increases exponentially with the number of particles involved. The result is a mechanism capable of breaching, on accessible time scales, the ergodic constraints in nano‐scale systems
Miniaturization and embedding of soliton-based electro-optically addressable photonic arrays
Using top-electrodes, we demonstrate the soliton-based miniaturized integration of electro-optic devices in a photorefractive paraelectric bulk crystal. Self-trapping and beam manipulation though soliton electro-activation is achieved at quasi-digital voltages
Evidence of double-loop hysteresis in disordered ferroelectric crystal
Double-loop electric-field vs polarization hysteresis is investigated in a depoled compositionally disordered lithium-enriched potassium tantalate niobate crystal. Comparing electro-optic response and dielectric spectroscopy indicates that the anomalous response occurs for those temperatures in which the sample also manifests a temperature hysteresis in the low-frequency dielectric function. An electric-field hysteresis at concurrent temperatures suggests an underlying role of reorienting mesoscopic polar regions that accompany the nonergodic phase. Published under license by AIP Publishing
Observation of replica symmetry breaking in disordered nonlinear wave propagation
A landmark of statistical mechanics, spin-glass theory describes critical phenomena in
disordered systems that range from condensed matter to biophysics and social dynamics.
The most fascinating concept is the breaking of replica symmetry: identical copies of the
randomly interacting system that manifest completely different dynamics. Replica symmetry
breaking has been predicted in nonlinear wave propagation, including Bose-Einstein
condensates and optics, but it has never been observed. Here, we report the experimental
evidence of replica symmetry breaking in optical wave propagation, a phenomenon that
emerges from the interplay of disorder and nonlinearity. When mode interaction dominates
light dynamics in a disordered optical waveguide, different experimental realizations are
found to have an anomalous overlap intensity distribution that signals a transition to an
optical glassy phase. The findings demonstrate that nonlinear propagation can manifest
features typical of spin-glasses and provide a novel platform for testing so-far unexplored
fundamental physical theories for complex systems