Stochastic resonance in vertical cavity surface emitting lasers

We report a detailed experimental investigation of stochastic resonance (SR) in the polarized emission of a pump-modulated vertical cavity surface emitting laser. We characterize SR in the time and frequency domains, with a quantitative agreement with existing theories. We further report a statistical analysis of SR in terms of residence-time probability distributions exhibiting alternative features which are fully explained here. By using an accurate choice of the indicator, we are also able to give clear evidence of bona fide resonance.     

Incoherent and coherent writing and erasure of cavity solitons in an optically pumped semiconductor amplifier

Cavity solitons in semiconductor amplifiers were, from the beginning of their study and observation, obtained either spontaneously or in a controlled manner by local coherent excitation. We describe two experiments that demonstrate coherent and, we believe for the first time, incoherent writing and erasure of cavity solitons in an optically pumped vertical-cavity semiconductor amplifier by short optical pulses.     

Excitability in a semiconductor laser with saturable absorber

We show that a monolithic and compact vertical cavity laser with intracavity saturable absorber can emit short excitable pulses. These calibrated optical pulses can be excited as a response to an input perturbation whose amplitude is above a certain threshold. Subnanosecond excitable response is promising for applications to novel all-optical devices for information processing or logical gates.     

Modeling pattern formation and cavity solitons in quantum dot optical microresonators in absorbing and amplifying regimes

We present a complete overview of our investigation past and present of the modelization and study of the spatiotemporal dynamics of a coherent field emitted by a semiconductor microcavity based on self-assembled quantum dots. The modelistic approach is discussed in relation to prospective growth and experimental research, and the model is then applied to resonators for which the medium is either passive (coherent photogeneration of carriers) or active (carrier pumping by current bias). The optical response of the system is investigated, especially in what concerns the linewidth enhancement factor, which turns out to be critical for the onset of self-organized patterns. The regimes in which one can expect bistable response, modulational instabilities, pattern formation, and cavity soliton formation are investigated. The pattern scenario is described, and experimentally achievable conditions are predicted for the occurrence of stable cavity solitons.     

Control of cavity solitons and dynamical states in a monolithic vertical cavity laser with saturable absorber

We present recent experimental results on the control and dynamics of cavity solitons in a monolithic, vertical cavity surface emitting laser with saturable absorber. On one hand, the fast and independent manipulation of two laser cavity solitons is achieved and a flip-flop operation is demonstrated with a single control-beam. On the other hand, a pulsing localized structure is presented and we demonstrate the control of a pulsing multispot structure that we can switch-on and off. These results are promising in view of the obtainment of a pulsed and monolithic cavity soliton laser.     

Fast manipulation of laser localized structures in a monolithic vertical cavity with saturable absorber

We show the spontaneous and controlled formation of bistable and localized laser spots in the transverse section of a monolithic vertical cavity laser with a saturable absorber. Successive incoherent writing and erasure is obtained up to 80 MHz repetition rate with a 60 ps localized excitation. We also show the formation of clusters of laser localized states. All these observations are in good qualitative agreement with existing models.     

Model for optical pattern and cavity soliton formation in a microresonator with self-assembled semiconductor quantum dots

We have developed a model that describes the optical response of a semiconductor quantum dot medium in a cavity in order to investigate pattern and cavity solitons formation. This model, beyond the inclusion of the inhomogeneous broadening of the quantum dot linewidth [1] (due the fluctuations of the quantum dot sizes that arise in self-organized growth), takes into account more complex phenomena such as the thermal escape and capture as well as Auger scattering mechanisms coupling the quantum dot itself with the wetting layer, and carrier diffusion in the unconfined directions of the wetting layer. We have studied the conditions for the onset of bistability and modulational instability and characterize the patterns formed at the bifurcated solutions. New features brought by these terms and indications on the most favourable regimes for cavity solitons formation are discussed. PACS 42.65.Sf; 42.65.An; 78.67.Hc     

Experimental evidence of binary aperiodic stochastic resonance

A novel kind of aperiodic stochastic resonance is experimentally studied in a vertical cavity surface emitting laser. We characterize the response of the system to a random, binary signal as a function of an applied external noise. A maximum in the input-output correlation is found for a nonzero added noise. We present analytic results with a good agreement with the measurements. We also discuss the physical meaning of the phenomenon using simple arguments, and we compare it to stochastic resonance.