Search results for "Toe"
showing 10 items of 3824 documents
Extreme statistics in Raman fiber amplifiers : from experiments to analytical description
2010
International audience; We describe the concept of an all-fibered device that enables the optical magnification of the amplitude jitter of low-fluctuation pulse trains, facilitating the measurement of the statistical properties by usual photodiodes and electronic equipments. Taking advantage of a highly nonlinear fiber with anomalous dispersion followed by central optical bandpass filtering, we experimentally demonstrate an amplification of small-scale fluctuations by a factor 10.
Double-seed stabilization of a continuum generated from fourth-order modulation instability
2013
Summary form only given. Modulation instability (MI) is a ubiquitous process in which a weak field is exponentially amplified through a balance between dispersive and nonlinear effects. In single-mode scalar optical fibers, the positive Kerr nonlinearity phase-mismatch can be compensated by anomalous second-order dispersion, a process known as MI2. But phase-matched solutions can also exist in normal second-order dispersion region, thanks to negative even higher-order terms [1]. This process, that we label MI4, gives rise to a pair of narrow sidebands widely detuned far from the pump. MI may grow spontaneously from broadband noise and is usually the main process involved in the early stages…
All-Fibered High-Quality 20-GHz and 40-GHz Picosecond Pulse Generator
2011
International audience; In this work, we investigate the generation of 20 and 40 GHz pulse trains by nonlinear compression of an initial beating in a cavity-less optical-fiber-based configuration. High temporal stability is obtained by generating the sinusoidal beating by means of an intensity modulator driven by an external clock. The residual timing jitter induced by the RF phase modulation is then reduced by managing the cumulated dispersion of the compression line whereas complete polarization stabilization is obtained thanks to a modified setup including a Faraday rotator mirror. Finally a high-quality 160 Gbit/s signal is generated from our low duty-cycle 40 GHz pulse source thanks to…
Complexes and Molecules of Dissipative Solitons in Mode-Locked Lasers
2009
Pulse-pulse interaction is a major issue in the development of high-repetition rate fiber laser sources or soliton-based optical transmission lines. The design of a suitable level of nonlinear dissipation, through nonlinear filters or saturable absorbers for instance, is able to improve significantly the stability of multiple pulse operation. The concept of a dissipative soliton has become an important tool for the exploration and the analysis of the multiple pulse dynamics, with mode-locked lasers and regenerated transmission lines as important applications [1,2]. Above all, the study of dissipative solitons has become a fertile area of nonlinear science with multidisciplinary implications…
Tailored soliton statistics in supercontinuum generation
2009
Supercontinuum (SC) generation in highly nonlinear photonic crystal fibers (PCF) has stimulated tremendous interest in recent years [1]. Particular results that have received recent widespread attention concern the observation of “optical rogue waves,” statistically rare extreme red-shifted Raman solitons appearing on the long wavelength edge of the SC spectrum [2]. Further numerical analysis of these fluctuations have showed explicitly that the rogue soliton statistics exhibit strongly non-Gaussian extreme-value characteristics [3]. The previous studies of optical rogue wave statistics in SC generation have been carried out considering PCF with only one zero dispersion wavelength (ZDW). It…
Optical flip-flop memory and data packet switching operation based on polarization bistability in a telecommunication optical fiber
2013
We report the experimental observation of bistability and hysteresis phenomena of the polarization signal in a telecommunication optical fiber. This process occurs in a counterpropagating configuration in which the optical beam nonlinearly interacts with its own Bragg-reflected replica at the fiber output. The proof of principle of optical flip–flop memory and 10 Gbit/s routing operation is also reported based on this polarization bistability. Finally, we also provide a general physical understanding of this behavior on the basis of a geometrical analysis of an effective model of the dynamics. Good quantitative agreement between theory and experiment is obtained.
Experimental demonstration of Bloch mode parity change in photonic crystal waveguide
2004
We experimentally show coupling between two photonic crystal waveguide Bloch modes having a different parity. A monomode ridge waveguide etched in a silicon-on-insulator substrate and connecting to the photonic crystal waveguide allows us to excite the even Bloch mode. Transmission measurements, performed on a broad spectral range, show the even mode propagation along the defect line. Then, spectrally resolved near-field patterns obtained by using a scanning near-field optical microscope in collection mode for wavelengths, inside and outside the multimode region of the photonic crystal waveguide, clearly demonstrate coupling phenomenon between even and odd modes.
Photon bunching of the nonlinear photoluminescence emitted by plasmonics metals
2021
International audience; In this report, we investigate the statistical temporal distribution of nonlinear upconverted photoluminescence emitted by gold and silver nanostructures excited by focused near-infrared laser pulses. We systematically observe a clear signature of photon bunching regardless of the nano-object's geometry, material's crystalline arrangement, and electronic band structure. The similarity of the data obtained across very different plasmonic objects confirms that these types of nonlinear radiation share a common chaotic origin and result from a collection of emitters. The correlation of photons at a picosecond time scale released by nanoscale nonlinear sources of broadban…
Extreme events in fiber based amplifiers
2009
International audience; We present experimental and theoretical results showing the emergence of rogue wave-like extreme intensity spikes during fiber-based amplification processes such as Raman effect or induced-modulational instability that rely on quasi-instantaneous gain. We outline that under certain circumstances, a partially incoherent pumping can induce large fluctuations of the amplified signal, and we propose various means to spectrally select the most extreme structures.
All-optical control and stabilization of the polarization state of a 10-Gbit/s RZ telecommunication signal
2010
International audience; We report the experimental observation of an all-fibered polarization attractor at telecommunication wavelengths. We experimentally show that is possible to all-optical control the state of polarization of a 10 Gbit/s telecommunication signal through the injection of a counterpropagating pump wave.