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Fuel cell (FC) is considered as one of the most interesting solutions to overcome future energy crisis announced by the International Energy Agency. However, various bottlenecks, whether technological or societal, slow the industrial interest for this technology and therefore the mass production of fuel cells. One of these bottlenecks is related to the limited lifetime of FC system. To counter it,...
Real time measurements of fluctuations during nonlinear pulse propagation in optical fibers present significant challenges, yet there is clearly much insight to be obtained in explicitly measuring shot-to-shot variation in pulse characteristics. This is especially the case in optical supercontinuum (SC) generation, where many different processes contribute to the spectral broadening, and isolating...
Entangled photons have appeared to be a promising way both for fundamental tests of physical principles and for quantum information applications such as Quantum Key Distribution. In particular, using entangled photons could potentially allow the realization of key distribution protocols over distances greater than a few hundreds of kilometers [1] and security certification without a priori trust in...
The opto-electronic oscillator is one of the most promising architecture for generating ultra-stable microwaves in the 0.1–100 GHz range. The idea consists in storing light energy instead of radio-frequency energy. This was usually achieved in a km-length fiber delay line [1,2], with the inconvenient of being bulky, energy-greedy, with a spectrum presenting spurious peaks that can be detrimental to...
Fiber supercontinuum (SC) generation is a well-known process widely studied over the last decade [1]. Recently, the particular case of noise-driven SC has received increasing attention because of novel instability properties and links with other systems in the formation of extreme events [2]. SC fluctuations have been investigated experimentally typically through RF measurements technique [3] or considering...
Photonic nonlinear transient computing (NTC) [1,2,3] is a physical implementation, in optics, of a novel brain inspired computational paradigm, also referred as to Echo State Network (ESN[4]), or Liquid State Machine (LSM[5]) and Reservoir Computing (RC[6]) in the early literature. The particular approach which very recently led to the first photonic demonstrations[1,3], have been using the dynamical...
Nonlinear delay dynamical systems have found several fundamental and applied issues in Optics [1], since delays from time of flight of the light becomes easily important, even with a few cm of fibers, compared to fast or even ultra-fast photonic response times. Fiber pigtailed modern Telecom devices can thus provide easy system design strategies to build well-controlled high complexity nonlinear delay...
Optical frequency combs have recently attracted a lot of attention due to their various potential applications in spectroscopy, metrology, sensing, microwave and terahertz generation, etc. While generally created in femtosecond mode-blocked lasers, frequency combs can be generated by cascaded four-wave-mixing (FWM) in optical resonators through the Kerr nonlinearity. In particular, whispering-gallery...
We present a novel scheme in which photonic information processing can be performed using a photonic system with delayed feedback. Inspired by the way our brain process information, we show that a single optoelectronic oscillator with delay can replace a complex network of nonlinear dynamical elements without losing performance.
This work reports on the first experimental photonic demonstration of a neuromorphic computational unit, on the basis of a recently proposed brain-inspired paradigm typically referred as Echo State Network, Liquid State Machine, or also Reservoir Computing in the neuronal computing literature. This paradigm makes use of the computational power offered by high dimensional transient motions developed...
Reservoir Computing is an emerging field of research intended to develop novel computational machines based on operating principles issued from the neural network community [1] and the brain research sciences [2]. Practical implementations of the corresponding principles is a strongly open question, which is precisely addressed from the photonic viewpoint in the frame of a recently funded EC project...
Random number generation is a central component of modern information technology, with crucial applications in ensuring communications and information security. The development of new physical mechanisms suitable to directly generate random bit sequences is thus a subject of intense current research, with particular interest in alloptical techniques suitable for the generation of data sequences with...
Electro-optic nonlinear delay dynamics are one of the main alternative approach to external cavity semiconductor lasers, in the context of experimental optical chaos communications setups [1]. In the frame of a recently accomplished European project (PICASSO, FP6-IST-2006-34551), we have demonstrated state of the art performances with a novel electro-optic approach involving the generation of chaotic...
A fundamental property of nonlinear dynamical systems controlled by a delayed feedback is their tendency to exhibit 2τ -periodic square-wave oscillations of equal plateau lengths (τ is the delay) [1]. The question was recently raised whether an optical system could exhibit stable square-wave oscillations with different plateau lengths [2]. We have experimentally found these regimes using a single...
Reservoir computing has recently been put forward as the generic name of a new research line in machine learning [1]. This field combines Echo State Networks, introduced by Jaeger [2], and Liquid State Machines, introduced by Maass [3]. These systems, that can be used to solve complex classification problems in a computationally efficient way, were proposed as an alternative to the recurrent neural...
Experimental tuning of a microwave photonic filter is achieved by varying the optical link length. Filtering effect is obtained by the interaction of an externally modulated multimode optical source and a dispersive channel. Experimental transmission of TV-signal using this filter is also described in this paper.
This article reports on the noise model of the OEO. The phase-noise and the amplitide-noise spectra can be predicted on the ground of the noise of the OEO internal components.
This study deals with a design, fabrication and characterization of compact optoelectronic oscillators (OEO). The resonator - a disk measuring a few millimeters in diameter with rounded edges - behaves as a sphere because the energy is trapped in whispering-gallery modes in the equatorial region. For this purpose, Fused silica and MgF2 are suitable, due to their mechanical characteristics and their...
We report on very recent achievements in optical chaos communications. Electro-optic phase modulation principles have been used to design a new chaos generator based on nonlinear delay dynamics. A multiple delay (both short and long) architecture allowed for an enhanced chaotic complexity, as well as a more accurate synchronization capability, over the full bandwidth of a typical 10 Gb/s binary message...
We have manufactured a high-Q whispering gallery mode resonator with magnesium fluoride for microwave photonics applications in the gigahertz frequency range. This crystal is scarcely used for resonator fabrication despite its numerous advantages, that are mainly high mechanical hardness, low sensitivity to water vapor pollution, and low sensitivity to photo- and thermo-refractive fluctuations at...
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