1,801 research outputs found
Dispersion-induced dynamics of coupled modes in a semiconductor laser with saturable absorption
We present an experimental and theoretical study of modal nonlinear dynamics
in a specially designed dual-mode semiconductor Fabry-Perot laser with a
saturable absorber. At zero bias applied to the absorber section, we have found
that with increasing device current, single mode self-pulsations evolve into a
complex dynamical state where the total intensity experiences regular bursts of
pulsations on a constant background. Spectrally resolved measurements reveal
that in this state the individual modes of the device can follow highly
symmetric but oppositely directed spiralling orbits. Using a generalization of
the rate equation description of a semiconductor laser with saturable
absorption to the multimode case, we show that these orbits appear as a
consequence of the interplay between the material dispersion in the gain and
absorber sections of the laser. Our results provide insights into the factors
that determine the stability of multimode states in these systems, and they can
inform the development of semiconductor mode-locked lasers with tailored
spectra.Comment: 10 pages, 10 figure
Arrest of Domain Coarsening via Antiperiodic Regimes in Delay Systems
Motionless domains walls representing heteroclinic temporal or spatial orbits
typically exist only for very specific parameters. This report introduces a
novel mechanism for stabilizing temporal domain walls away from the Maxwell
point opening up new possibilities to encode information in dynamical systems.
It is based on anti-periodic regimes in a delayed system close to a bistable
situation, leading to a cancellation of the average drift velocity. The results
are demonstrated in a normal form model and experimentally in a laser with
optical injection and delayed feedback.Comment: 6 pages, 5 figures, resubmitted manuscrip
Delayed feedback control of self-mobile cavity solitons in a wide-aperture laser with a saturable absorber
We investigate the spatiotemporal dynamics of cavity solitons in a broad area
vertical-cavity surface-emitting laser with saturable absorption subjected to
time-delayed optical feedback. Using a combination of analytical, numerical and
path continuation methods we analyze the bifurcation structure of stationary
and moving cavity solitons and identify two different types of traveling
localized solutions, corresponding to slow and fast motion. We show that the
delay impacts both stationary and moving solutions either causing drifting and
wiggling dynamics of initially stationary cavity solitons or leading to
stabilization of intrinsically moving solutions. Finally, we demonstrate that
the fast cavity solitons can be associated with a lateral mode-locking regime
in a broad-area laser with a single longitudinal mode
Bifurcation structure of cavity soliton dynamics in a VCSEL with saturable absorber and time-delayed feedback
We consider a wide-aperture surface-emitting laser with a saturable absorber
section subjected to time-delayed feedback. We adopt the mean-field approach
assuming a single longitudinal mode operation of the solitary VCSEL. We
investigate cavity soliton dynamics under the effect of time- delayed feedback
in a self-imaging configuration where diffraction in the external cavity is
negligible. Using bifurcation analysis, direct numerical simulations and
numerical path continuation methods, we identify the possible bifurcations and
map them in a plane of feedback parameters. We show that for both the
homogeneous and localized stationary lasing solutions in one spatial dimension
the time-delayed feedback induces complex spatiotemporal dynamics, in
particular a period doubling route to chaos, quasiperiodic oscillations and
multistability of the stationary solutions
Fundamentals and applications of spatial dissipative solitons in photonic devices : [Chapter 6]
We review the properties of optical spatial dissipative solitons (SDS). These are stable, self‐localized optical excitations sitting on a uniform, or quasi‐uniform, background in a dissipative environment like a nonlinear optical cavity. Indeed, in optics they are often termed “cavity solitons.” We discuss their dynamics and interactions in both ideal and imperfect systems, making comparison with experiments. SDS in lasers offer important advantages for applications. We review candidate schemes and the tremendous recent progress in semiconductor‐based cavity soliton lasers. We examine SDS in periodic structures, and we show how SDS can be quantitatively related to the locking of fronts. We conclude with an assessment of potential applications of SDS in photonics, arguing that best use of their particular features is made by exploiting their mobility, for example in all‐optical delay lines
Physics and Applications of Laser Diode Chaos
An overview of chaos in laser diodes is provided which surveys experimental
achievements in the area and explains the theory behind the phenomenon. The
fundamental physics underpinning this behaviour and also the opportunities for
harnessing laser diode chaos for potential applications are discussed. The
availability and ease of operation of laser diodes, in a wide range of
configurations, make them a convenient test-bed for exploring basic aspects of
nonlinear and chaotic dynamics. It also makes them attractive for practical
tasks, such as chaos-based secure communications and random number generation.
Avenues for future research and development of chaotic laser diodes are also
identified.Comment: Published in Nature Photonic
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