1,253 research outputs found
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.
Stability analysis of polarization attraction in optical fibers
The nonlinear cross-polarization interaction among two intense
counterpropagating beams in a span of lossless randomly birefringent telecom
optical fiber may lead to the attraction an initially polarization scrambled
signal towards wave with a well-defined state of polarization at the fiber
output. By exploiting exact analytical solutions of the nonlinear polarization
coupling process we carry out a linear stability study which reveals that
temporally stable stationary solutions are only obtained whenever the output
signal polarization is nearly orthogonal to the input pump polarization.
Moreover, we predict that polarization attraction is acting in full strength
whenever equally intense signal and pump waves are used
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
Dynamics of the Modulational Instability in Microresonator Frequency Combs
A study is made of frequency comb generation described by the driven and
damped nonlinear Schr\"odinger equation on a finite interval. It is shown that
frequency comb generation can be interpreted as a modulational instability of
the continuous wave pump mode, and a linear stability analysis, taking into
account the cavity boundary conditions, is performed. Further, a truncated
three-wave model is derived, which allows one to gain additional insight into
the dynamical behaviour of the comb generation. This formalism describes the
pump mode and the most unstable sideband and is found to connect the coupled
mode theory with the conventional theory of modulational instability. An
in-depth analysis is done of the nonlinear three-wave model. It is demonstrated
that stable frequency comb states can be interpreted as attractive fixed points
of a dynamical system. The possibility of soft and hard excitation states in
both the normal and the anomalous dispersion regime is discussed.
Investigations are made of bistable comb states, and the dependence of the
final state on the way the comb has been generated. The analytical predictions
are verified by means of direct comparison with numerical simulations of the
full equation and the agreement is discussed.Comment: 9 pages, 6 figures, submitted to Phys. Rev.
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
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
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
Mitigation of Nonlinear and PMD Impairments by Bit-Synchronous Polarization Scrambling
Our statistical study by the importance sampling method shows that a significant performance improvement may be achieved by bit-synchronous polarization scrambling in the presence of polarization mode dispersion and fiber nonlinearity in dispersion managed, single-channel, or wavelength- division- multiplexed NRZ 10 Gbit/s fiber optic transmission systems
Silicon Raman Polarizer
We theoretically investigate the polarization properties of Raman amplifiers based on silicon-on-insulator waveguides, and show that it is possible to realize a waveguide Raman polarizer. The Raman polarizer is a special type of Raman amplifier with the property of producing an amplified and highly repolarized beam when it is fed by a relatively weak and unpolarized signal
Analytical method for designing dispersion-managed fiber systems
This paper was published in Optics Letters and is made available as an electronic reprint with the permission of OSA. The paper can be found at the following URL on the OSA website: http://www.opticsinfobase.org/abstract.cfm?URI=ol-26-20-1544. Systematic or multiple reproduction or distribution to multiple locations via electronic or other means is prohibited and is subject to penalties under law.Peer reviewedPublisher PD
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