Search results for "Linear optics"
showing 10 items of 493 documents
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…
Ultra-high repetition all optical picosecond pulsed sources : applications in optical telecommunications
2013
This thesis presents the work carried out on the realization of fibered 40-GHz picosecond optical pulse sources in the telecommunications C-band. In the first part, we present a numerical and experimental study of the generation of 40-GHz pulse trains thanks to the nonlinear compression of an initial beat-signal by multiple Four-Wave Mixing process. Enhanced temporal stability is achieved by generating the sinusoidal beating thanks to a Mach-Zehnder modulator driven at its zero-transmission working point. In order to improve the quality of the generated pulses, we also demonstrate the suppression of stimulated Brillouin back-scattering by inserting several optical isolators into the compres…
Complex rogue wave in the fiber optics
2016
This manuscript presents the generation of complex rogue waves related to nonlinear instabilities occurring through the propagation of light in standard optical fibers. Linear and nonlinear physical phenomena involved are first listed, in particular some of them by analogy with the field of hydrodynamics. The different forms of rogue waves induced by the modulation instability process are then presented. They are also known as "breathers", and they are obtained by solving the nonlinear Schrödinger equation. From these exact solutions, various experimental systems were designed by means of numerical simulations based on two rogue-wave excitation methods. The first one is an exact generation …
Generation of parabolic pulses and applications for optical telecommunications
2009
International audience; Parabolic pulses in optical fibers have stimulated an increasing number of applications. We review here the physics underlying the generation of such self-similar pulses as well as the results obtained in a wide-range of passive or active experimental configurations.
Observation of light-by-light polarization control and stabilization in optical fibre for telecommunication applications
2010
International audience; In many photonics applications, especially in optical fibre based systems, the state of polarization of light remains so far an elusive uncontrolled variable, which can dramatically affect the performances of that systems and which one would like to control as finely as possible. Here, we experimentally demonstrate light-by-light polarization control via a nonlinear effect occurring in single mode optical fibre. We observe a polarization attraction and stabilization of a 10 Gbit/s optical telecommunication signal around 1550 nm. We also validate the potentiality of the device to annihilate very fast nanosecond polarization bursts. This result confirms yet another fas…
On recent progress in all-fibered pulsed optical sources from 20 GHz to 2 THz based on multiple four wave mixing approach
2009
International audience; In this paper, we report recent progress on the design of all-fibered ultra-high repetition-rate pulse sources for telecommunication applications around 1550 nm. Based on the nonlinear compression of an initial beat-signal in optical fibers through a multiple four-wave mixing process, we theoretically and experimentally demonstrate that this simple technique allows an efficient and accurate design of versatile pulse sources having repetition rates and pulse durations ranging from 20 GHz up to 2 THz and from 10 ps up to 110 fs, respectively.
Second zero dispersion wavelength measurement through soliton self-frequency shift compensation in suspended core fibre
2008
International audience; A simple experimental technique to evaluate the second zero dispersion wavelength of very small core microstrutured fibres is described. Based on the effect of soliton self-frequency shift and its subsequent compensation in the vicinity of the second zero dispersion. the proposed method is applied to both standard and suspended core microstructured fibres by simply measuring the frequency stabilised soliton spectrum, avoiding any calculation and knowledge of any experimental parameters.
Spatiotemporal beam shaping in nonlinear multimode fibers
2018
Kerr beam self-cleaning in graded-index multimode fibers is accompanied by power-dependent temporal pulse reshaping. We explore the complex nonlinear dynamics with a single long pulse, where the optical power is continuously varied across its profile.
Universal soliton pattern formations in passively mode-locked fiber lasers
2011
International audience; We investigate multiple-soliton pattern formations in a figure-of-eight passively mode-locked fiber laser. Operation in the anomalous dispersion regime with a double-clad fiber amplifier allows generation of up to several hundreds of solitons per round trip. We report the observation of remarkable soliton distributions: soliton gas, soliton liquid, soliton polycrystal, and soliton crystal, thus indicating the universality of such complexes.
Fiber-based light source for biomedical applications
2013
This manuscript presents the work done concerning the development of a light source used for biomedical imaging and more particularly for coherent Raman scattering imaging. In fact an efficient broadcasting of these ones is hampered by the need of two synchronized and wavelength shifted pulses. As so, the handiness and frequency conversion capabilities of nonlinear fiber optics are used to circumvent this technological lock. First of all, an easy wavelength tunable source is set by the use of the self-shifting in optical frequency of a soliton. A study of the main fiber parameters lead to shifts of 320 to more than 500 nm which allows interesting molecular resonances imaging (≈ 1000-4000 cm…