26 research outputs found
Temporal summation in a neuromimetic micropillar laser
Neuromimetic systems are systems mimicking the functionalities orarchitecture
of biological neurons and may present an alternativepath for efficient
computing and information processing. We demonstratehere experimentally
temporal summation in a neuromimetic micropillarlaser with integrated saturable
absorber. Temporal summation is theproperty of neurons to integrate delayed
input stimuli and to respondby an all-or-none kind of response if the inputs
arrive in a sufficientlysmall time window. Our system alone may act as a fast
optical coincidence detector and paves the way to fast photonic spike
processing networks
Experimental Study of Noise-induced Phase Synchronization in Vertical-cavity Lasers
We report the experimental evidence of noise-induced phase synchronization in
a vertical cavity laser. The polarized laser emission is entrained with the
input periodic pump modulation when an optimal amount of white, gaussian noise
is applied. We characterize the phenomenon, evaluating the average frequency of
the output signal and the diffusion coefficient of the phase difference
variable. Their values are roughly independent on different waveforms of
periodic input, provided that a simple condition for the amplitudes is
satisfied. The experimental results are compared with numerical simulations of
a Langevin model
Spatiotemporal chaos induces extreme events in an extended microcavity laser
Extreme events such as rogue wave in optics and fluids are often associated
with the merging dynamics of coherent structures. We present experimental and
numerical results on the physics of extreme events appearance in a spatially
extended semiconductor microcavity laser with intracavity saturable absorber.
This system can display deterministic irregular dynamics only thanks to spatial
coupling through diffraction of light. We have identified parameter regions
where extreme events are encountered and established the origin of this
dynamics in the emergence of deterministic spatiotemporal chaos, through the
correspondence between the proportion of extreme events and the dimension of
the strange attractor
Optical bistability in a GaAs based polariton diode
We report on a new type of optical nonlinearity in a polariton p-i-n
microcavity. Abrupt switching between the strong and weak coupling regime is
induced by controlling the electric field within the cavity. As a consequence
bistable cycles are observed for low optical powers (2-3 orders of magnitude
less than for Kerr induced bistability). Signatures of switching fronts
propagating through the whole 300 microns x 300 microns mesa surface are
evidenced.Comment: 5 pages 3 figure
Polarization-mode hopping in single-mode vertical-cavity surface-emitting lasers: Theory and experiment.
In this paper, we present a theoretical and experimental analysis of stochastic effects observed in polarization switching vertical-cavity surface-emitting lasers. We make a thorough comparison between theoretical predictions and experiments, comparing measured quasipotentials and dwell times. The correspondence between our theoretical model based on stochastic intensity rate equations and the experiments is found to be very good
Two distinct excitable responses for a laser with a saturable absorber
Excitable lasers with saturable absorbers are currently investigated as potential candidates for low level spike processing tasks in integrated optical platforms. Following a small perturbation of a stable equilibrium, a single and intense laser pulse can be generated before returning to rest. Motivated by recent experiments [Selmi, Phys. Rev. E 94, 042219 (2016)10.1103/PhysRevE.94.042219], we consider the rate equations for a laser containing a saturable absorber (LSA) and analyze the effects of different initial perturbations. With its three steady states and following Hodgkin classification, the LSA is a Type I excitable system. By contrast to perturbations on the intensity leading to the same intensity pulse, perturbations on the gain generate pulses of different amplitudes. We explain these distinct behaviors by analyzing the slow-fast dynamics of the laser in each case. We first consider a two-variable LSA model for which the conditions of excitability can be explored in the phase plane in a transparent manner. We then concentrate on the full three variable LSA equations and analyze its solutions near a degenerate steady bifurcation point. This analysis generalizes previous results [Dubbeldam, Phys. Rev. E 60, 6580 (1999)1063-651X10.1103/PhysRevE.60.6580] for unequal carrier density rates. Last, we discuss a fundamental difference between neuron and laser models.SCOPUS: ar.jinfo:eu-repo/semantics/publishe