ASCHIERI , Pierre

The purpose of this article is to analyze the impact of an index segmentation on the ray dispersion in the geometrical approach. The presented study re- veals that a periodic index segmentation of the waveguide along with a trans- verse gaussian index variation exhibits complex ray dynamics that strongly modify ray dispersion properties.

In this article it is shown that for specific initial conditions an input beam injected in a Multimode Periodic Segmented Waveguides (MPSW) does not di ract and remains collimated all along the waveguide whereas a speckle like pattern is expected at the output of a multimode structure. This nonintuitive behavior can be explained with the help...

In this article it is shown that for specific initial conditions an input beam injected in a Multimode Periodic Segmented Waveguides (MPSW) does not di ract and remains collimated all along the waveguide whereas a speckle like pattern is expected at the output of a multimode structure. This nonintuitive behavior can be explained with the help...

n this article, it is shown that multimode periodic segmented waveguides (PSW) are versatile optical systems in which properties of wave chaos can be highlighted. Numerical wave analysis reveals that structures of quantum phase space of PSW are similar to Poincare sections which ́ display a mixed phase space where stability islands are...

The purpose of this article is to show that efficient light coupling in lithium niobate waveguides presenting a strongly confined mode, such as photonic wires, is possible with the use of a periodically segmented waveguide coupler. The coupler consists in an input periodically segmented waveguide whose mode size is adapted to the mode of a...

In this article, we present a numerical analysis concerning ray propagation in a multimode periodic segmented waveguide with a gaussian index segment profile. We show that this simple waveguide configuration exhibits a complex ray dynamics that can be regular or chaotic depending on the initial conditions.

The mirrorless backward optical parametric oscillator (BOPO), where the signal and idler waves are propagating in opposite directions, will establish a distributed feedback mechanism and thus optical parametric oscillation without the need to apply mirrors or external feedback to the cavity. It has been recently demonstrated experimentally by...

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In optical parametric oscillators based on periodically poled (PP) non-linear quadratic materials, choosing a submicronic poling period allows generating the phase-matched signal and idler waves in opposite directions. In this case a distributed feedback mechanism is established, which enables optical parametric oscillation without the need of...

We model a backward mirrorless optical parametric oscillator in a fragmented GaN waveguide consisting in a sequence of submicronic periodically poled elements separated by uniformly polarized connection sections representing stitching errors. We find that the generated coherent phase of the backscattered wave locks the phases of the forward...

This article presents a scheme for few-mode EDFA, which allows to choose independent amplification lengths for different mode groups. The EDF is a dual concentric core fiber, where the central core is connected to the line FMF and the ring core is doped with erbium to provide amplification. The modes of FMF are launched into the central core of...

The modes properties of highly multimode optical fibre are governed by the rays' dynamics in the geometrical limit. Different regimes of dynamics are encountered by modifying the geometry of the transverse cross section of the fibers. We show that the selection of modes in a highly multimode fiber can be simplied thanks to the signature of the...

RÉSUMÉ: Nous proposons une analyse numérique d'une fibre amplifiant les groupes de modes LP11 et LP21 d'une fibre faiblement multimode avec un gain modal différentiel ajustable. La fibre se compose d'un cœur central et d'un cœur annulaire qui est dopé aux ions Er3+. Les modes du cœur central de la fibre amplificatrice sont excités par les modes...

An original concept of integrated few-mode erbium doped fibre ampli- fier for mode division multiplexing (MDM) reaches nearly zero differ- ential modal gain between two mode groups (8 MDM channels) with more than 20 dB of gain.

This article proposes an original concept of a dual-concentric-core few-mode erbium doped fiber (EDF) for amplification of the LP11 and LP21 mode groups of a few mode fiber (FMF) at 1530-nm wavelength with controlled differential modal gain (DMG). The proposed EDF consists of a central core and a ring core. The ring core is doped with Er3+ ions...

A combination of loss properties of Periodic Segmented Waveguides and second-order wavelength conversion processes is shown to exhibit features which allow to realize an adjustable optical power limiter using classical integrated optics technologies. Results of numerical simulations are presented to confirm the viability of the proposed...

Three-wave solitons backward propagating with respect to a pump wave are generated in nonlinear optical media through stimulated Brillouin scattering (SBS) in optical fibers or through the non-degenerate three-wave interaction in quadratic (χ (2)) nonlinear media. In an optical fiber-ring cavity, nanosecond solitary wave morphogenesis takes...

Parametric downconversion in submicronic periodically poled (PP) quadratic materials allows for the generation of signal and idler waves in opposite directions. The distributed feedback mechanism enables a backward mirrorless optical parametric oscillator (BMOPO), which has been experimentally realized using a periodically poled KTiOPO(PPKTP)...

Parametric downconversion in submicronic periodically poled (PP) quadratic materials allows the generation of signal and idler waves in opposite directions. The distributed feedback mechanism enables a backward mirrorless optical parametric oscillator (BMOPO), which has been experimentally realized using a periodically-poled KTP crystal with...

One of the unique features of mirrorless optical parametric oscillators based on counterpropagating three-wave interactions is the narrow spectral width of the wave generated in the backward direction. In this work, we in- vestigate experimentally and numerically the influence that a strong phase modulation in the pump has on the spectral...

We propose a new mode adapter which allows more efficient launching of the optical power selectively in the fundamental mode of a multimode waveguide. Theoretical and experimental results confirm that such a mode adapter increases the performances in terms of coupling efficiency, coupling tolerances and transmitted power with respect to...

The proton exchange technique allows fabricating a great variety of waveguides in Lithium Niobate. Recently we discovered that it was possible to realize highly confining waveguides in a controllable manner and without destroying the nonlinear and electro-optic properties of the crystal. With this technique, one can fabricate quantum wires in...

We present the results of an experimental study of waveguide tapers realized in LiNbO3 using the soft-protonexchange process and the waveguide segmentation technique. Measurements show that they can be favorably introduced between the nonlinear or electrooptic part of the components, which require strong mode confinement to increase efficiency,...

Waves billiard which are chaotic in the geometrical limit are known to support non-generic spatially localized modes called scar modes. The interaction of the scar modes with gain has been recently investigated in optics in micro-cavity lasers and vertically-cavity surface-emitting lasers. Exploiting the localization properties of scar modes in...