Spatiotemporal chaos and order in fiber lasers

We introduce a model that permits the unified description of the emergence of different regimes of complex temporal structures in noise-like or quasi-CW fiber lasers. The model is based on the vector Ginzburg-Landau equation that also permits to reproduce the experimentally observed polarization antiphase behavior and the synchronization of spatiotemporal turbulence into polarizations domain wall solitons

Dual pumped microresonator frequency combs

A study is made of the nonlinear dynamics of dual pumped microresonator Kerr frequency combs described by a driven and damped nonlinear Schr\"odinger equation, with an additional degree of freedom in the form of the modulation frequency. A truncated four wave model is derived for the pump modes and the dominant sideband pair which is found to be able to describe much of the essential dynamical behaviour of the full equation. The stability of stationary states within the four wave model is investigated and numerical simulations are made to demonstrate that a large range of solutions, including cavity solitons, are possible beyond previously considered low intensity patterns.Comment: 7 pages, 9 figures, submitted to Phys. Rev.

Optical tsunamis: shoaling of shallow water rogue waves in nonlinear fibers with normal dispersion

In analogy with ocean waves running up towards the beach, shoaling of prechirped optical pulses may occur in the normal group-velocity dispersion regime of optical fibers. We present exact Riemann wave solutions of the optical shallow water equations and show that they agree remarkably well with the numerical solutions of the nonlinear Schr\"odinger equation, at least up to the point where a vertical pulse front develops. We also reveal that extreme wave events or optical tsunamis may be generated in dispersion tapered fibers in the presence of higher-order dispersion

Modulational instability of nonlinear polarization mode coupling in microresonators

We investigate frequency comb generation in the presence of polarization effects induced by nonlinear mode coupling in microresonator devices. A set of coupled temporal Lugiato-Lefever equations are derived to model the propagation dynamics, and an in-depth study is made of the modulational instability of their multistable homogeneous steady-state solutions. It is shown that new kinds of instabilities can occur for co-propagating fields that interact through nonlinear cross-phase modulation. These instabilities display properties that differ from their scalar counterpart, and are shown to result in the generation of new types of incoherently coupled frequency comb states.Comment: 8 pages, 7 figure

On the numerical simulation of Kerr frequency combs using coupled mode equations

It is demonstrated that Kerr frequency comb generation described by coupled mode equations can be numerically simulated using Fast Fourier Transform methods. This allows broadband frequency combs spanning a full octave to be efficiently simulated using standard algorithms, resulting in orders of magnitude improvements in the computation time.Comment: 3 pages, 1 figure, submitted to Optics Communication

Bragg grating rogue wave

We derive the rogue wave solution of the classical massive Thirring model, that describes nonlinear optical pulse propagation in Bragg gratings. Combining electromagnetically induced transparency with Bragg scattering four-wave mixing, may lead to extreme waves at extremely low powers

Parametric Frequency Conversion of Short Optical Pulses Controlled by a CW Background

We predict that parametric sum-frequency generation of an ultra-short pulse may result from the mixing of an ultra-short optical pulse with a quasi-continuous wave control. We analytically show that the intensity, time duration and group velocity of the generated idler pulse may be controlled in a stable manner by adjusting the intensity level of the background pump

Optical turbulence in fiber lasers

We analyse the nonlinear stage of modulation instability in passively mode locked fiber lasers leading to chaotic or noise-like emission. We present the phase transition diagram among different regimes of chaotic emission in terms of the key cavity parameters: amplitude or phase turbulence, and spatio-temporal intermittency

Comment on GHz pulse train generation in fiber lasers by cavity induced modulation instability

A recent invited paper (Tang et al., 2014) reports the experimental observation of the generation of stable pulse trains in a ring fiber laser with repetition rates varying in the range between 3 GHz and 285 GHz. Contrary to what is stated, the theory published in that invited paper does not support the claim that the generation mechanism of the pulse train is the cavity induced modulation instability effect