424 research outputs found
Nonlinear graphene plasmonics: amplitude equation
Using perturbation expansion of Maxwell equations, the amplitude equation is
derived for nonlinear TM and TE surface plasmon waves supported by graphene.
The equation describes interplay between in-plane beam diffraction and
nonlinerity due to light intensity induced corrections to graphene conductivity
and susceptibility of dielectrics. For strongly localized TM plasmons, graphene
is found to bring the superior contribution to the overall nonlinearity. In
contrast, nonlinear response of the substrate and cladding dielectrics can
become dominant for weakly localized TE plasmons.Comment: published in Phys. Rev.
Intrinsic bistability and dual-core dark solitons and vortices in exciton polariton condensates
We investigate a new kind of dark solitons and vortices that can exist in the
exciton-polariton condensates. These structures have discontinuity in the
excitonic part of the polaritonic field and exist due to an intrinsic
multiplicity of the solutions for the exciton density in the given optical
field. Reported solutions are characterized by two very distinct localization
scales, and hence are coined as dual-core dark solitons and vortices
Classical and quantum radiation of perturbed discrete breathers
We show that the linearized phase space flow around a discrete breather
solution is not capable of generating persistent energy flow away from the
breather even in the case of instabilities of extended states. This holds both
for the classical and quantized description of the flow. The main reason for
that is the parametric driving the breather provides to the flow. Corresponding
scaling arguments are derived for both classical and quantum cases. Numerical
simulations of the classical flow support our findings.Comment: 8 pages, 3 figure
Spectral-discrete solitons and localization in frequency space
We report families of discrete optical solitons in frequency space, or
spectral-discrete solitons existing in a dispersive Raman medium, where
individual side-bands are coupled by coherence. The associated time-domain
patterns correspond to either trains of ultrashort pulses, or weakly modulated
waves. We describe the physics behind the spectral localization and study
soliton bifurcations, stability and dynamics.Comment: 4 pages, 4 figures, submitted to Opt. Let
Amplification of surface plasmon polaritons in the presence of nonlinearity and spectral signatures of threshold crossover
We describe effects of nonlinearity on propagation of surface plasmon
polaritons (SPPs) at an interface between a metal and an amplifying medium of
the externally pumped two-level atoms. Using Maxwell equations we derive the
nonlinear dispersion law and demonstrate that, the nonlinear saturation of the
linear gain leads to formation of stationary SPP modes with the intensities
independent from the propagation distance. Transition to the regime of
stationary propagation is similar to the threshold crossover in lasers and
leads to narrowing of the SPP spectrum.Comment: http://www.opticsinfobase.org/ol/abstract.cfm?uri=ol-34-18-286
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