99 research outputs found
Interface localized modes and hybrid lattice solitons in waveguide arrays
We discuss the formation of guided modes localized at the interface separat-
ing two different periodic photonic lattices. Employing the effective discrete
model, we analyze linear and nonlinear interface modes and also predict the
existence of stable interface solitons including the hybrid
staggered/unstaggered lattice solitons with the tails belonging to spectral
gaps of different types.Comment: 11 pages, 5 figures, submitted to Opt. Let
Two-color surface lattice solitons
We study the properties of surface solitons generated at the edge of a
semi-infinite photonic lattice in nonlinear quadratic media, namely two-color
surface lattice solitons. We analyze the impact of phase mismatch on existence
and stability of surface modes, and find novel classes of two-color twisted
surface solitons which are stable in a large domain of their existence.Comment: 4 pages, 5 figures, Submitted for publicatio
Interface solitons in two-dimensional photonic lattices
We analyze localization of light at the interface separating square and
hexagonal photonic lattices, as recently realized experimentally in
two-dimensional laser-written waveguide arrays in silica glass with
self-focusing nonlinearity [A. Szameit {\em et al.}, Opt. Lett. {\bf 33}, 663
(2008)]. We reveal the conditions for the existence of {\em linear} and {\em
nonlinear} surface states substantially influenced by the lattice topology, and
study the effect of the different symmetries and couplings on the stability of
two-dimensional interface solitons.Comment: 3 pages, 4 figures, submitted to Opt. Let
Observation of two-dimensional lattice interface solitons
We report on the experimental observation of two-dimensional solitons at the
interface between square and hexagonal waveguide arrays. In addition to the
different symmetry of the lattices, the influence of a varying refractive index
modulation depth is investigated. Such variation strongly affects the
properties of surface solitons residing at different sides of the interface.Comment: 14 pages, 5 figures, to appear in Optics Letter
Nonlinear localized modes at phase-slip defects in waveguide arrays
We study light localization at a phase-slip defect created by two
semi-infinite mismatched identical arrays of coupled optical waveguides. We
demonstrate that the nonlinear defect modes possess the specific properties of
both nonlinear surface modes and discrete solitons. We analyze stability of the
localized modes and their generation in both linear and nonlinear regimes.Comment: 3 pages, 6 figures, submitted to Opt. Let
Discrete surface solitons in semi-infinite binary waveguide arrays
We analyze discrete surface modes in semi-infinite binary waveguide arrays,
which can support simultaneously two types of discrete solitons. We demonstrate
that the analysis of linear surface states in such arrays provides important
information about the existence of nonlinear surface modes and their
properties. We find numerically the families of both discrete surface solitons
and nonlinear Tamm (gap) states and study their stability properties.Comment: 3 pages, 4 figures, submitted to Opt. Let
Discrete surface solitons in two-dimensional anisotropic photonic lattices
We study nonlinear surface modes in two-dimensional {\em anisotropic}
periodic photonic lattices and demonstrate that, in a sharp contrast to
one-dimensional discrete surface solitons, the mode threshold power is lower at
the surface, and two-dimensional discrete solitons can be generated easier near
the lattice corners and edges. We analyze the crossover between effectively
one- and two-dimensional regimes of the surface-mediated beam localization in
the lattice.Comment: 3 pages, 4 figure
Discrete and surface solitons in photonic graphene nanoribbons
We analyze localization of light in honeycomb photonic lattices restricted in
one dimension which can be regarded as an optical analog of (``armchair'' and
``zigzag'') graphene nanoribbons. We find the conditions for the existence of
spatially localized states and discuss the effect of lattice topology on the
properties of discrete solitons excited inside the lattice and at its edges. In
particular, we discover a novel type of soliton bistability, the so-called
geometry-induced bistability, in the lattices of a finite extent.Comment: three double-column pages, 5 figures, submitted for publicatio
Observation of localized modes at phase slips in two-dimensional photonic lattices
We study experimentally light localization at phase-slip waveguides and at
the intersection of phase-slips in a two-dimensional (2D) square photonic
lattice. Such system allows to observe a variety of effects, including the
existence of spatially localized modes for low powers, the generation of
strongly localized states in the form of discrete bulk and surface solitons, as
well as a crossover between one-dimensional (1D) and 2D localization.Comment: 4 double-column pages, 6 figures, submitted for publicatio
Observation of surface solitons in chirped waveguide arrays
We report the observation of surface solitons in chirped semi-infinite
waveguide arrays whose waveguides exhibit exponentially decreasing refractive
indices. We show that the power threshold for surface wave formation decreases
with an increase of the array chirp and that for sufficiently large chirp
values linear surface modes are supported.Comment: 12 pages, 3 figures, to appear in Optics Letter
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