96 research outputs found
A phase-space approach to directional switching in semiconductor ring lasers
We show that a topological investigation of the phase space of a
Semiconductor Ring Laser can be used to devise switching schemes which are
alternative to optical pulse injection of counter-propagating light. To provide
physical insight in these switching mechanisms, a full bifurcation analysis and
an investigation of the topology is performed on a two-dimensional asymptotic
model. Numerical simulations confirm the topological predictions.Comment: 9 pages, 7 figure
Excitability in semiconductor microring lasers: Experimental and theoretical pulse characterization
We characterize the operation of semiconductor microring lasers in an
excitable regime. Our experiments reveal a statistical distribution of the
characteristics of noise-triggered optical pulses that is not observed in other
excitable systems. In particular, an inverse correlation exists between the
pulse amplitude and duration. Numerical simulations and an interpretation in an
asymptotic phase space confirm and explain these experimentally observed pulse
characteristics.Comment: 9 pages, 10 figure
Exploring multi-stability in semiconductor ring lasers: theory and experiment
We report the first experimental observation of multi-stable states in a
single-longitudinal mode semiconductor ring laser. We show how the operation of
the device can be steered to either monostable, bistable or multi-stable
dynamical regimes in a controlled way. We observe that the dynamical regimes
are organized in well reproducible sequences that match the bifurcation
diagrams of a two-dimensional model. By analyzing the phase space in this
model, we predict how the stochastic transitions between multi-stable states
take place and confirm it experimentally.Comment: 4 pages, 5 figure
Topological insight into the non-Arrhenius mode hopping of semiconductor ring lasers
We investigate both theoretically and experimentally the stochastic switching
between two counter-propagating lasing modes of a semiconductor ring laser.
Experimentally, the residence time distribution cannot be described by a simple
one parameter Arrhenius exponential law and reveals the presence of two
different mode-hop scenarios with distinct time scales. In order to elucidate
the origin of these two time scales, we propose a topological approach based on
a two-dimensional dynamical system.Comment: 4 pages, 3 figure
Novel integrated tunable laser using filtered feedback for simple and very fast tuning
We present a novel integrated tunable laser based on filtered feedback, which combines a simple tuning method with ns switching speed
Integrated filtered-feedback tunable laser with enhanced control of feedback phase
Recently we presented a novel discretely tunable laser that consists of a Fabry-Perot laser which was forced to operate in single-mode condition by applying on-chip filtered feedback. The laser switches extremely fast (3 ns) and requires simple on/off control currents to switch the wavelength. In these first devices it was not possible to control the phase of the feedback light independently from the feedback intensity. In was solved by adding an extra electrode allowing us to control the phase separately. In this paper we present the new device and study the effect of the control ofthefeedbackphase in order to improve the performance ofthe original tunable laser concept
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