Search results for "Nonlinear optic"
showing 10 items of 530 documents
Discrete spectral incoherent solitons in nonlinear media with noninstantaneous response
2011
International audience; We show theoretically that nonlinear optical media characterized by a finite response time may support the existence of discrete spectral incoherent solitons. The structure of the soliton consists of three incoherent spectral bands that propagate in frequency space toward the low-frequency components in a discrete fashion and with a constant velocity. Discrete spectral incoherent solitons do not exhibit a confinement in the space-time domain, but exclusively in the frequency domain. The kinetic theory describes in detail all the essential properties of discrete spectral incoherent solitons: A quantitative agreement has been obtained between simulations of the kinetic…
Generation and Coherent Control of Pulsed Quantum Frequency Combs
2018
We present a method for the generation and coherent manipulation of pulsed quantum frequency combs. Until now, methods of preparing high-dimensional states on-chip in a practical way have remained elusive due to the increasing complexity of the quantum circuitry needed to prepare and process such states. Here, we outline how high-dimensional, frequency-bin entangled, two-photon states can be generated at a stable, high generation rate by using a nested-cavity, actively mode-locked excitation of a nonlinear micro-cavity. This technique is used to produce pulsed quantum frequency combs. Moreover, we present how the quantum states can be coherently manipulated using standard telecommunications…
Observation of elastic anisotropy in strained optical nanofibers using Brillouin spectroscopy
2019
Optical nanofibers (ONFs) are excellent nanophotonic platforms for many applications such as optical sensing, quantum photonics, and nonlinear optics, due to both tight optical confinement and their evanescent field. From an acoustic viewpoint, it has recently been reported the observation of a new class of Brillouin acoustic resonances in optical nanofibers, including hybrid shear/longitudinal acoustic waves (HAWs) and surface acoustic waves (SAWs) [1–2]. It has been later shown that, under axial tensile strain, the Brillouin frequency shifts (BFS) of these elastic resonances are fundamentally different from that of standard optical fibers [3]. This is principally due to the hybrid nature …
Roadmap on optical rogue waves and extreme events
2016
Nail Akhmediev et al. ; 38 págs.; 28 figs.
Effects of rapid thermal annealing on the optical properties of low-loss 1.3μm GaInNAs∕GaAs saturable Bragg reflectors
2004
We report studies of the effect of rapid thermal annealing (RTA) on the optical properties of a low-loss 1.3 mum saturable Bragg reflector (SBR), consisting of a GaInNAs/GaAs single quantum well embedded in an AlAs/GaAs Bragg reflector grown monolithically on a GaAs substrate. RTA gives rise to a blueshift of the photoluminescence (PL) peak (and therefore of the excitonic absorption peak) and an enhancement of PL intensity, while the reflectivity properties including peak reflectivity and bandwidth are not degraded. Temperature dependent photoluminescence measurements show that the RTA-induced blueshift of photoluminescence consists of two components: one originating from the increase of op…
Light-induced transmission nonlinearities in gallium selenide
1999
The intensity of a He–Ne laser (633 nm, 5 mW) transmitted by different GaSe samples is observed to change in correlation with a Nd-yttrium–aluminum–garnet laser pulse (532 nm, 7.8 ns, 3 mJ) which excites them. Such time response has been attributed to a nonlinear optical effect, i.e., a decrease in the refractive index due to the exciton screening by the photogenerated carriers. A calculation of the absorption coefficient and refractive index at different carrier concentrations has led to a reconstruction of transmittance transients which fully agree with the experimental data at different incident intensities and temperatures. Chantal.Ferrer@uv.es ; Jaqueline.Bouvier@uv.es ; Miguel.Andres@…
Optical Studies of Amphiphilic Molecules with Interesting Electro-Optical and Non-Linear Optical Properties
1990
Structural control is a major issue in both life science, investigating the function of the biological machinery, and in materials science, aiming at the design of novel devices. In part one, recent electro-optical investigations of the primary event of photosynthesis on purified protein preparations are described. Part two focuses on structural studies of monolayers at an air/water interface, and of Langmuir-Blodgett multilayers from a new molecule designed for nonlinear optical applications.
Ondes scélérates et statistiques extrêmes dans les systèmes optiques fibrés
2011
This thesis deals with extremes statistics which has become an attractive subject in optics since a comparison with oceanic rogue waves has been proposed at the end of 2007. We report some potential mechanisms stimulating the rogue wave formation in the context of guided propagation of light in optical fibers. In a first part, we explore optical rogue waves in supercontinuums generated by fourth-order modulation instability and we propose a stabilization method based on the use of two continuous seeds. Then, we present a detailed study on Raman fiber amplifiers where we determine the conditions of emergence of giant structures : in presence of a partially incoherent pumping wave, a quasi-in…
Beneficial impact of wave-breaking for coherent continuum formation in normally dispersive nonlinear fibers
2008
International audience; We study the evolution of a pulse propagating in a normally dispersive fiber in the presence of Kerr nonlinearity. We review the temporal and spectral impact of optical wave-breaking in the development of a continuum. The impact of linear losses or gain is also investigated.
Computationally efficient dynamical analysis of optically driven injection-locked GaAs FET oscillators
1995
A computer-aided simulation technique for the dynamical analysis of a class of GaAs FET optically-driven injection-locked oscillators (ODILO's) is presented. By combining a measurement-derived nonlinear model of the illuminated transistor with a phasor-domain analysis method, a first-approximation - but phenomenologically complete - differential model of the synchronized oscillator is derived. Since amplitude and phase of waveform evolutions are directly addressed and evaluated in a stroboscopic-time scale, the calculation of the transient response to modulated input signals can be done in a more user-friendly and computationally efficient manner than possible through conventional time-doma…