Search results for " optical fiber"
showing 10 items of 327 documents
Nonlinear virtues of multimode fibre
2015
The finding that multimode optical fibres support a rich and complex mix of spatial and temporal nonlinear phenomena could yield a plethora of promising applications.
Kerr self-cleaning of pulsed beam in an ytterbium doped multimode fiber
2017
International audience; We experimentally demonstrate that Kerr spatial self-cleaning of a pulsed beam can be obtained in an amplifying multimode optical fiber. An input peak power of 500 W only was sufficient to produce a quasi-single-mode emission from the double-clad ytterbium doped multimode fiber (YMMF) with non-parabolic refractive index profile. We compare the self-cleaning behavior observed in the same fiber with loss and with gain. Laser gain introduces new opportunities to achieve spatial self-cleaning of light in multimode fibers at a relatively low power threshold.
Mid-infrared strong spectral broadening in microstructured tapered chalcogenide AsSe fiber
2012
We report on the generation of a supercontinuum in a chalcogenide microstructured tapered fiber. The suspended core diameter of the fiber is reduced from 5.5 μm to 0.8 μm in the waist of the tapered region. The zero dispersion wavelength is below 2 μm in the tapered region. To pump the fiber, we use a modelocked laser of 4 ps, with a central wavelength of 1960 nm. With only 150 W peak power in the fiber a supercontinuum is generated from 1300 to 2600 nm taking the supercontinuum wavelength edge at -30 dB from the continuum.
Extreme statistics in Raman fiber amplifiers : influence of pump depletion and dispersion
2010
OSA 2010 NonLinear Photonics Best Student Poster Award; International audience; We experimentally and theoretically investigate the influence of pump depletion effects on extreme statistics observed in fiber Raman amplifiers. We also report on the impact of the dispersion of the fiber.
Nonlinear femtosecond pulse propagation in all-solid photonic bandgap fiber
2009
Nonlinear femtosecond pulse propagation in all-solid photonic bandgap fiber is investigated experimentally and numerically for both the photonic bandgap guiding in the central silica core and the total internal reflection in germanium doped inclusions.
Interface engineering for improved light transmittance through photonic crystal flat lenses
2010
In this paper, we present photonic crystal flat lenses with interfaces engineered to improve the light transmittance thanks to a broad angles impedance matching. The interface engineering consists in the realization of antireflection gratings on the edges of the lenses which are designed to reduce the propagative waves reflectivity over a wide range of incident angles. The fabricated structures were measured in optical near-field and a four times enhancement of the light transmission efficiency is reported.
Bloch mode coupling investigation in silicon-on-insulator W1 photonic crystal waveguide
2004
We report in this paper the study of a W1 photonic crystal waveguide which supports two Bloch modes having 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, evidence the even mode propagation along the defect line and experimental spectrum is discussed in light of band diagram and FDTD calculations. 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 wav…
Shallow water rogue waves in nonlinear optical fibers
2013
The dynamics of extreme waves, often known as freak or rogue waves (RW), is presently a subject of intensive research. In oceanography, RW are mostly known as a sudden deep-water event which is responsible for ship wreakages and can be modeled by the 1D Nonlinear Schrodinger Equation (NLSE). In this framework, an ideal testbed is provided by optical pulse propagation in nonlinear optical fibers: extreme solitary wave emissions during supercontinuum generation or the first experimental observation of the Peregrine solitons have indeed been carried out exploiting the modulation instability occuring in fibers with anomalous dispersion.
Spatio-temporal beam dynamics in multimode nonlinear optical fibers
2017
We overview recent advances in the spatio-temporal nonlinear dynamics of optical pulses propagating in multimode optical fibers. The Kerr effect leads to spatial beam self-cleaning in a graded-index multimode optical fiber, followed by sideband series generation spanning multiple octaves. Effectively single mode supercontinuum spanning from the visible to the mid-infrared was also demonstrated. Enhancement of Kerr beam self-cleaning was observed in active fiber with quasi-step index profile. Moreover, mutual self-cleaning was recently reported for both the fundamental and the second harmonic beams in optically poled multimode fibers with cubic and quadratic nonlinearity.
Nonlinear spatial self-cleaning in multimode amplifying fiber and fiber laser cavity
2017
During the last years, multimode fibers (MMFs) were used as an experimental platform for the observation of complex nonlinear propagation phenomena, thanks to their additional spatiotemporal degrees of freedom with respect to single mode fibers. Multimode solitons [1], geometric parametric instability [2], self-induced beam cleaning (SBC) [3] and supercontinuum generation have been reported [4]. In all of these situations considered so far the MMFs were standard graded-index fibers: the intermodal interactions took place in a conservative system (propagation losses were negligible). In this work we have experimentally investigated the Kerr SBC in three dissipative systems: a MMF with signif…