97 research outputs found
Complex photonic nonlinear delay dynamics for high performance signal and information processing
International audienceOptoelectronic delayed feedback loops can provide a wide variety of dynamical motions, thanks to their infinite dimensional phase space. When implemented with Telecom grade components, they additionally provide broadband operation, particularly suited for high speed signal and information processing. On the basis on experimental illustration, we will introduce the fundamental nonlinear dynamical properties of photonic delayed feedback systems, from their stable fixed point operation to their high dimensional complex chaotic oscillations, through periodic oscillations. Each of these particular solution will then be further developed to demonstrate advanced information and signal processing capabilities, from secure optical chaos communications at 10Gb/s, to ultra-fast million word per second recognition through neuromorphic computing, through microwave high spectral purity oscillations for radar applications
Determination of phase noise spectra in optoelectronic microwave oscillators: a Langevin approach
We introduce a stochastic model for the determination of phase noise in
optoelectronic oscillators. After a short overview of the main results for the
phase diffusion approach in autonomous oscillators, an extension is proposed
for the case of optoelectronic oscillators where the microwave is a limit-cycle
originated from a bifurcation induced by nonlinearity and time-delay. This
Langevin approach based on stochastic calculus is also successfully confronted
with experimental measurements.Comment: 18 pages, 7 figures, 11 references. Submitted to IEEE J. of Quantum
Electronics, May 200
Photonic nonlinear transient computing with multiple-delay wavelength dynamics
International audienceWe report on the experimental demonstration of a hybrid optoelectronic neuromorphic computer based on a complex nonlinear wavelength dynamics including multiple delayed feedbacks with randomly defined weights. This neuromorphic approach is based on a new paradigm of a brain-inspired computational unit, intrinsically differing from Turing machines. This recent paradigm consists in expanding the input information to be processed into a higher dimensional phase space, through the nonlinear transient response of a complex dynamics excited by the input information. The computed output is then extracted via a linear separation of the transient trajectory in the complex phase space. The hyperplane separation is derived from a learning phase consisting of the resolution of a regression problem. The processing capability originates from the nonlinear transient, resulting in nonlinear transient computing. The computational performance is successfully evaluated on a standard benchmark test, namely, a spoken digit recognition task
Temporal dynamics of Kerr frequency combs in whispering-gallery mode resonators
International audienceBased on a modal description of the evolution of the mode's amplitude in a whispering-gallery mode resonator, we numerically study the generation of Kerr combs. We show that a stable primary comb appear for pump power slightly above threshold, enabling potential applications in metrology. For high input power however, chaotic signals are observed
On phase locking phenomena in Kerr combs
International audienceBased on a modal description of the evolution Kerr combs in a whispering-gallery mode resonator, we numerically investigate the phase bhavior of the different spectral lines of the spectrum. We show that a stable phase relation exists between adjacent modes in primary combs. This result is of great interest for metrological applications where one phase noise is an issue. For high input power however, chaotic signals are observed
Mismatch-Induced Bit Error Rate in Optical Chaos Communications Using Semiconductor Lasers With Electrooptical Feedback
8 pages, 8 figures.We analyze the influence of parameter mismatch between emitter and receiver systems on the bit error rate of an optical chaos communication scheme. Intensity hyperchaos is generated in the system by semiconductor lasers with electro-optical feedback. We find analytical predictions for the dependence of the bit error rate with the amplitude of the various mismatches and the statistical properties of the hyperchaotic carrier. A good concordance is found with numerical and experimental results.This work was supported in part by the European Commission through the research project OCCULT under Contract IST-2000-29683, in part by the the MEC (Spain) and FEDER under Projects FIS2004-00953 (CONOCE2), BFM2001-0341-C02-02 (SINFIBIO), and TIC2001-4572-E, and in part by a research grant from the Govern de les Illes Balears.Peer reviewe
Effect of fiber dispersion on broadband chaos communications implemented by electro-optic nonlinear delay phase dynamics
We investigate theoretically and experimentally
the detrimental e ect of ber dispersion on the synchroniza-
tion of an optoelectronic phase chaos cryptosystem. We
evaluate the root-mean square synchronization error and
the cancellation spectra between the emitter and the re-
ceiver in order to characterize the quality of the optical
ber communication link. These two indicators explicitly
show in temporal and spectral domain how ber dispersion
does negatively a ect the phase chaos cancellation at the re-
ceiver stage. We demonstrate that the dispersion manage-
ment techniques used in conventional optical ber networks,
such as dispersion-compensating modules/ bers or disper-
sion shifted bers, are also e cient to strongly reduce the
detrimental e ects of ber propagation in phase chaos com-
munications. This compatibility therefore opens the way to
a successful integration of more than 10-Gb/s phase chaos
communications systems in existing networks, even when
the ber link spans over more than 100 km.Peer reviewe
Dynamic instabilities of microwaves generated with optoelectronic oscillators
3 pages.-- OCIS codes: 120.3940, 190.3100, 350.4010.-- Final full-text version of the paper available at: http://dx.doi.org/10.1364/OL.32.002571.We introduce a time-domain model to study the dynamics of optoelectronic oscillators. We show that, due to the interaction between nonlinearity and time delay, the envelope amplitude of ultrapure microwaves generated by optoelectronic oscillators can turn unstable when the gain is increased beyond a given critical value. Our analytical predictions are confirmed by numerical simulations and experiments.Y. K. C. acknowledges a research grant from the Govern de les Illes Balears. Financial support from EC project PICASSO IST-2005-34551, MEC (Spain) and FEDER project TEC2006-1009/MIC (PhoDECC) is also acknowledged
Time-domain dynamics and stability analysis of optoelectronic oscillators based on whispering-gallery mode resonators
International audienceOptoelectronic oscillators (OEOs) are microwave photonics systems intended to generate ultrastable radio-frequency signals with unprecedented phase noise performance for aerospace and communication engineering applications. They had originally been introduced in a configuration where the energy storage element was a fiber delay line. However, recent research in view of size and power consumption optimization has led to novel configurations where this fiber delay line is replaced by an ultrahigh Q whispering-gallery mode (WGM) resonator. So far, there has been no theoretical framework enabling to understand the dynamical behavior of these new architectures of OEOs. In this paper, we propose for the first time a deterministic time-domain model to investigate the dynamics of these OEOs based on WGM resonators. This model enables us to perform the stability analysis of the microwave oscillations, and to determine rigorously their range of stability as the loop gain is varied. After building the model, we perform a full stability analysis of the various stationary solutions for the microwave output. We then perform extensive numerical simulations, which are in complete agreement with the stability analysis. The theoretical analysis is also found to be in excellent agreement with our experimental measurements
Estimation of the uncertainty for a phase noise optoelectronic metrology system
International audienceThe configuration of the phase noise measurement system operating in the X-band (8.2-12.4 GHz) using a photonic delay line as a frequency discriminator is presented in this paper. This system does not need any excellent frequency reference and works for any frequency in this band. Oscillator frequency fluctuation is converted into phase frequency fluctuation through the delay line. The measured phase noise includes the device under test noise and the instrument background. Then the use of a cross correlation decreases the cross spectrum terms of uncommon phase noise as √(1/m), where m is the average number. Using cross correlation on 500 averages, the noise floor of the instrument £(f) becomes, respectively, −150 and −170 dBc Hz−1 at 101 and 104 Hz from the 10 GHz carrier (−90 and −170 dBc Hz−1 including 2 km delay lines). We then focus on determining the uncertainty. There are two categories of uncertainty terms: 'type A', statistic contributions such as repeatability and experimental standard deviation; 'type B' due to various components and temperature control. The elementary term of uncertainty for repeatability is found to be equal to 0.68 dB. Other elementary terms still have lower contributions. This leads to a global uncertainty of 1.58 dB at 2σ
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