Search results for "Dispersion"
showing 10 items of 1101 documents
Optical waveform tailoring in passive and laser cavity fibre systems
2019
International audience; The interplay among the effects of dispersion, nonlinearity and gain/loss in optical fibres is a powerful tool to generate a broad range of pulse shapes with tuneable properties. Here we propose a method to optimise the systems parameters for a given pulse target. By reducing the system complexity and applying machine-learning strategies, we show that it is possible to efficiently identify the sets of parameters of interest. Two configurations are numerically investigated: pulse shaping in a passive normally dispersive fibre and pulse generation in a dual-pump nonlinear-amplifying-loop-mirror mode-locked fibre laser.
New developments in the study of optical parabolic pulses in normally dispersive fibers
2011
International audience; We report two recent studies dealing with the evolution of parabolic pulses in normally dispersive fibers. On the one hand, the nonlinear reshaping from a Gaussian intensity profile towards the asymptotic parabolic shape is experimentally investigated in a Raman amplifier. On the other hand, the significant impact of the fourth order dispersion on a passive propagation is theoretically discussed: we numerically demonstrate flat-top, coherent supercontinuum generation in an all-normal dispersion-flattened photonic crystal fiber. This shape is associated to a strong reshaping of the temporal profile what becomes triangular.
Parabolic pulse formation and applications
2009
Parabolic pulses in optical fibers have stimulated an increasing number of applications. We review here the physics underlying the generation of such pulses as well as the results obtained in a wide-range of experimental configurations.
All-optical measurement of residual chromatic dispersion and OSNR using self-phase modulation in optical fiber
2011
International audience; We describe a new all-fibered device providing high accuracy all-optical measurements of both optical signal to noise ratio and residual chromatic dispersion. Taking advantage of the self-phase modulation driven spectral evolution of pulses propagating in a highly non-linear medium, we have numerically and experimentally validated the benefits of using an anomalous dispersive fiber combined with a central spectral filtering.
2R regeneration architectures based on multi-segmented fibres
2008
The benefits of using a multi-segmented arrangement of optical fibres for Self-Phase Modulation-based 2R optical regeneration are described both theoretically and experimentally. Significant improvements in terms of the performance and practicality are achieved.
Analysis of the Bloch mode spectra of surface polaritonic crystals in the weak and strong coupling regimes: grating-enhanced transmission at oblique …
2004
The Bloch mode spectrum of surface plasmon polaritons (SPPs) on a finite thickness metal film has been analyzed in the regimes of weak and strong coupling between SPP modes on the opposite film interfaces. The SPP mode dispersion and associated field distributions have been studied. The results have been applied to the description of the light transmission through thick and thin periodically structured metal films at oblique incidence. In contrast to normal incidence, all SPP Bloch modes on a grating structure participate in the resonant photon tunnelling leading to the transmission enhancement. However, at the angle of incidence corresponding to the crossing of different symmetry film SPP …
Experimental parabolic pulse generation with an active dispersion decreasing fiber
2008
We experimentally demonstrate the use of an hybrid configuration to generate parabolic pulses. We combine dispersion decrease with distributed gain. This leads to several benefits on the parabolic generated pulses compared with a passive configuration.
Chalcogenide microstructured optical fibers : from linear to nonlinear properties
2010
International audience; In this talk, we review the linear properties of chalcogenide microstructured optical fibers (MOFs) of several types. We mainly focus our talk on mid-infrared applications of such fibers. We start with the general properties of solid core MOFs made of these high index glasses and compare them with the ones of silica. Then, we give some details concerning a solid core MOF made of TAS glass. Next, we describe the first guiding suspended chalcogenide MOF and explain how it was designed for supercontinuum generation in the mid-infrared. Both linear and nonlinear properties of As2S3 suspended core MOFs are also numerically studied. In the next part, We describe the design…
Optical bullets and "rockets" in nonlinear dissipative systems and their transformations and interactions
2006
We demonstrate the existence of stable optical light bullets in nonlinear dissipative media for both cases of normal and anomalous chromatic dispersion. The prediction is based on direct numerical simulations of the (3+1)-dimensional complex cubic-quintic GinzburgLandau equation. We do not impose conditions of spherical or cylindrical symmetry. Regions of existence of stable bullets are determined in the parameter space. Beyond the domain of parameters where stable bullets are found, unstable bullets can be transformed into >rockets> i.e. bullets elongated in the temporal domain. A few examples of the interaction between two optical bullets are considered using spatial and temporal interact…
Impact of structural irregularities on high-bite-rate pulse compression techniques in photonics crystal fibre
2008
International audience; The impact of structural irregularities on high bit rate pulse compression techniques is evaluated in photonic crystal fibre. Specifically, more robust pulse compression to longitudinal fluctuations in the normal dispersion regime is reported. The physical limits of these pulse compression techniques in the presence of dispersion fluctuations are identified and the fact that state-of-the-art fabrication tolerances are sufficient for future experimental applications is confirmed.