Génération de supercontinuum par cascade de mélanges à quatre ondes intermodaux dans une fibre optique multimode à saut d'indice

International audience

Réalisation de sources d'impulsions optiques pico- et femto-secondes à 1555 nm cadencées de 20-GHz à 1-THz

National audience

Laser Raman fibré délivrant des impulsions nanosecondes aux longueurs d'ondes des télécommunications

National audience

Collision de similaritons optiques dans un amplificateur optique fibré Raman

National audience; Nous abordons les aspects théoriques et expérimentaux de la génération et propagation de deux similaritons optiques de fréquences centrales différentes dans un amplificateur optique fibré Raman à dispersion normale. Nous observons les effets intervenant durant la collision des deux similaritons: un battement sinusoïdal apparaît dans la zone de recouvrement temporel des impulsions et des effets de la modulation de phase croisée modifient le spectre des similaritons. Les similaritons retrouvent néanmoins, après collision, leurs caractéristiques paraboliques.

Nonlinear repolarization dynamics in optical fibers:transient polarization attraction

Spatiotemporal Nonlinear Interactions in Multimode Fibers

International audience

All-optical regeneration at 160-bit/s using a saturable absorber vertical microcavity

International audience

Stimulated Raman-Spectroscopy as the Essential Tool for Studying Collisional Effects - Application to Combustion

3rd International Conference: Laser M2P DEC 08-10, 1993 LYON, FRANCE FEDERAT LASER CTR, RHONE ALPES REG; The main purposes of this paper are to give an overview of coherent Raman techniques with a particular emphasis on Stimulated Raman Spectroscopy (SRS) because this process can be considered as an essential tool for investigating collisional processes.

Laser impulsionnel Raman à verrouillage de modes passif fonctionnant à 1 GHz.

Nous présentons un laser Raman impulsionnel à verrouillage de modes passif, assuré par l'évolution non linéaire de polarisation, et fonctionnant sur des harmoniques supérieures à 24000.

Line mixing in the stimulated Raman spectrum of the ν1 band of SiH4 at 0.4-1.0 bar

International audience; The stimulated Raman spectrum of the ν1 band of SiH4 has been recorded at 0.4 and 1.0 bar pressures and room temperature. Line mixing of the fine structure components of this spectrum was taken into account in a calculated profile by considering coupling between the main transitions and using a simple model (strong collision model, SCM) for the relaxation matrix.

A Powerful Tool to Study Collisional Phenomena and for Combustion Applications - the High-Resolution Stimulated Raman-Spectroscopy

0302-0738

FIBER AND GUIDED WAVE OPTICS | Nonlinear Effects (Basics)

Study of Collisional Effects on Band Shapes of the v1/2v2 Fermi Dyad in CO2 Gas with Stimulated Raman-Spectroscopy .2. Simultaneous Line Mixing and Dicke Narrowing in the v1 Band

0021-9606

Line Coupling Effects in Anisotropic Raman Q-Branches of the ν1/2ν2 Fermi Dyad in CO2

0021-9606; The generalized energy corrected sudden model is used to calculate the Q branch of the anisotropic coherent anti-Stokes Raman scattering spectra corresponding to the v1 and 2v2 transitions of the Fermi dyad of CO2. The corresponding experimental spectra have been recorded for pressures leading to a consistent overlapping between the rotational components. This leads to a new experimental evaluation of the relaxation time of the second-order tensor associated with the rotational angular momentum. The value is in excellent agreement with that already obtained from the study of the infrared absorption Q branch, the Rayleigh scattering, and the viscomagnetic effect. (C) 1995 American…

SOLITONS | Optical Fiber Solitons, Physical Origin and Properties

High-Resolution Stimulated Raman-Spectroscopy with a 3 MHz Accuracy Wavemeter

0302-0738

Thermalization of incoherent nonlinear waves

International audience

Optical Fibers Enter a New Space-Time Era

International audience

Spatiotemporal Nonlinear Beam Shaping

International audience

Study of Collisional Effects on Band Shapes of the ν1/2ν2 Fermi Dyad in CO2 Gas with Stimulated Raman-Spectroscopy .3. Modeling of Collisional Narrowing and Study of Vibrational Shifting and Broadening at High-Temperature

0021-9606; High resolution stimulated Raman spectra (SRS) of the ν1/2ν2 Fermi dyad of CO2 have been recorded in the 0.4-22. amagat density range at 700 K and in the 0.6-16 amagat density range at 900 K. The data have been successfully analyzed with a theoretical model taking into account both rotational line mixing through the energy corrected sudden-polynomial (ECS-P) law for the relaxation matrix and vibrational line broadening gamma(v) and line shifting delta(v). The two vibrational parameters have been accurately determined from fit to the experimental spectra. These new high temperature data together with previous data obtained at 295 and 500 K [B. Lavorel et al., J. Chem. Phys. 93, 21…

Broad-spectrum frequency comb generation from continuous waves

International audience

Determination of Temperature by Stimulated Raman Scattering of Molecular Nitrogen, Oxygen, and Carbon-Dioxide

0721-7269; We have determined the temperature from SRS spectra of N2-N2, N2-CO2, O2-O2, and CO2-CO2 recorded in wide pressure and temperature ranges. The fitting procedure takes simultaneously into account the Dicke effect and motional narrowing. We have quantified the accuracy of the MEG and ECS-P models for rotational relaxation. The temperature extracted from each model is compared with thermocouple measurements. The influence of vibrational broadening and shifting is discussed in detail.

All-optical measurements of background, amplitude, and timing jitters for high speed pulse trains or PRBS sequences using autocorrelation function

International audience; We present a simple method for all-optical measurements of background, amplitude, and timing jitters of ultra high speed pulse trains or PRBS sequences using the jitter dependence of the intercorrelation-peak shape. This method is numerically and experimentally demonstrated on a 42.66 Gbit/s PRBS sequence and then applied to measure the jitter growths occurring during the propagation of a 160-GHz pulse train in a classical SMF/DCF dispersion map.

Thermalization of random nonlinear waves: Application to optical waves

International audience

SCATTERING | Scattering Phenomena in Optical Fibers

Impulsions paraboliques et similaritons dans les fibres optiques

National audience

Nonlinear Raman Spectroscopy in Gases

0022-2860; Recent progress in high-resolution non-linear coherent Raman spectroscopy in the gas phase is reviewed. An instrumental spectral resolution of less than 100 MHz can be routinely achieved. It is limited by the convoluted linewidths of the lasers used for excitation and is of particular advantage in the gas phase, where the rotational structure of vibrational bands is to be resolved. It also allows the measurement of linewidths and line positions with an accuracy of 60 MHz when an appropriate wavemeter is used for calibration. After a short overview of the various techniques being used, examples of recent results of the evaluation of measurements on nitrogen, oxygen, carbon dioxide…

Study of ν1/ν3 interacting bands of silane : analysis of infrared and Raman spectra

International audience; The ν1/ν3 interacting bands of natural silane have been studied by Fourier transform spectroscopy and stimulated Raman spectroscopy, respectively, in the regions 2040–2320 and 2180–2187 cm−1. These data combined with available microwave observations have been analyzed using a reduced effective Hamiltonian developed through the fifth order for 28SiH4 and through the fourth order for 29SiH4 and 30SiH4. The observed infrared and Raman transitions have been very well reproduced with a standard deviation of about 0.0004 cm−1 for 28SiH4. Some anomalies in the Hamiltonian expansion have been found, but they did not perturb the analysis.

Fitting and scaling laws for high temperature Q branch collapse in the O2 stimulated Raman spectra in O2-H2O mixtures

0021-9606

Solitons to supercontinuum: New nonlinear structures in fiber propagation

International audience

Seeding of modulation instability in a nonlinear fiber ring cavity

International audience