32 research outputs found
Stable radiating gap solitons and their resonant interactions with dispersive waves in systems with parametric pump
We study the formation of gap solitons in the presence of parametric pump. It
is shown that parametric pump can stabilize stationary solitons continuously
emitting dispersive waves. The resonant interactions of the radiation and the
solitons are studied and it is shown that the solitons can be effectively
controlled by the radiation. In particular it is shown that the solitons can
collide or to get pinned to inhomogeneities due to the interactions mediated by
the resonant radiation
Chaotic Bloch oscillations in dissipative optical systems driven by a periodic train of coherent pulses
We study the response of an optical system with the Kerr nonlinearity
demonstrating Bloch oscillations to a periodic train of coherent pulses. It has
been found out that the intensity of the field excited in the system by pulses
resonantly depends on the train period. It is demonstrated numerically and
analytically that the response of the system is stronger when the period of the
driving pulses is commensurate with the period of the Bloch oscillations.
Moreover, large enough pulses are capable to induce the instabilities which
eventually lead to onset of chaotic Bloch oscillations of the wave-function
envelope bouncing both in time and space. The analysis reveals that these
instabilities are associated with period-doubling bifurcations. A cascade of
such bifurcations with increase of the pulses amplitude triggers the chaotic
behaviour
Discrete solitons in coupled active lasing cavities
We examine the existence and stability of discrete spatial solitons in
coupled nonlinear lasing cavities (waveguide resonators), addressing the case
of active defocusing media, where the gain exceeds damping in the low-amplitude
limit. A new family of stable localized structures is found: these are bright
and grey cavity solitons representing the connections between homogeneous and
inhomogeneous states. Solitons of this type can be controlled by the discrete
diffraction and are stable when the bistability of homogenous states is absent.Comment: 3 pages, 3 figures, accepted to Optics Letters (October 2012
Multi-frequency radiation of dissipative solitons in optical fiber cavities
New resonant emission of dispersive waves by oscillating solitary structures in optical fiber cavities is considered analytically and numerically. The pulse propagation is described in the framework of the Lugiato-Lefever equation when a Hopf-bifurcation can result in the formation of oscillating dissipative solitons. The resonance condition for the radiation of the dissipative oscillating solitons is derived and it is demonstrated that the predicted resonances match the spectral lines observed in numerical simulations perfectly. The complex recoil of the radiation on the soliton dynamics is discussed. The reported effect can have importance for the generation of frequency combs in nonlinear microring resonators
Solitons and frequency combs in silica microring resonators: Interplay of the Raman and higher-order dispersion effects
The influence of Raman scattering and higher order dispersions on solitons
and frequency comb generation in silica microring resonators is investigated.
The Raman effect introduces a threshold value in the resonator quality factor
above which the frequency locked solitons can not exist and, instead, a rich
dynamics characterized by generation of self-frequency shift- ing solitons and
dispersive waves is observed. A mechanism of broadening of the Cherenkov
radiation through Hopf instability of the frequency locked solitons is also
reported.Comment: 12 pages, 10 figure
Modulational instability of discrete solitons in coupled waveguides with group velocity dispersion
We study temporal modulational instability of spatial discrete solitons in waveguide arrays with group velocity dispersion (GVD). For normal GVD we report existence of the strong 'neck'-type instability specific for the discrete solitons. For anomalous GVD the instability leads to formation of the mixed discrete-continuous spatio-temporal quasi-solitons. Feasibility of experimental observation of these effects in the arrays of silicon-on-insulator waveguides is discussed