Elisabeth Brun

Experimental demonstration of second-order average soliton propagation in an optical fiber over several soliton periods

The propagation of second-order average solitons in fiber loop with lumped amplifiers over several soliton periods is demonstrated experimentally and numerically for the first time to our knowledge. The numerical model gives the effect of the amplifier noise on the soliton stability, and the results agree well with the observations.

Second-order average soliton jitter in long-haul transmission systems

The noise generated by amplifiers in an amplified optical link is responsible for the second-order average soliton decay into its fundamental soliton components. A simple assumption of independent fundamental soliton jitters allows the calculation of the theoretical performance of transmission systems employing such pulses.

Solitons in long-haul communications systems

Summary form only given. A promising technology for long-haul optical fiber transmission is provided by soliton systems. Soliton transmission controlled by sliding frequency guiding filtering enables higher line bit-rates (10-20 Gbit/s), longer amplifier spans (i.e., 63 km), and substantially longer transmission distances (10-20 mm). The performance of such passively controlled soliton systems is limited by timing jitter (Gordon-Haus effect and interactions). Such a limit can be overcome by in-line optical regeneration, as based on synchronous modulation. In this paper the current state-of-the-art in transmission capacity, concerning both passive and active soliton systems, is described.

Génération ďimpulsions picosecondes avec des lasers à semiconducteur pour les transmissions par soliton sur fibre optique

Recent developments in soliton transmission on optical fiber require picosecond pulses at 1.5 μm which are as close as possible to the Fourier transform limit. In the present paper, semiconductor lasers in pulsed regime are studied for this purpose. Thus, performances achievable by using the most usual methods, mode-locking and gain-switching, are evaluated. The aim of the last part is to discuss the design and performances of sources dedicated to soliton transmission as well as to present the principle of operation of a monolithic source based on a two- or three-section laser. The first results obtained with a three sections dbr laser are given.RésuméLe développement important des transmissions sur fibre optique utilisant les solitons nécessite de disposer a la longueur ď onde de 1,5 μm ď impulsions optiques picoseconde proche de la limite de la transformation de Fourier. Dans ce but, une analyse des lasers a semiconducteur en régime impulsionnel est proposée. Les auteurs évaluent les performances que ľ on peut attendre des deux méthodes qui sont classiquement utilisées pour générer ces impulsions avec des lasers à semiconducteur : le blocage de modes et la commutation de gain. Le but de la dernière partie est de discuter la réalisation et les performances des sources spécialement conçues pour les applications soliton ainsi que de présenter le principe de fonctionnement ď une source monolithique utilisant un laser multisection. Les premiers résultats obtenus avec un composant dbr à trois sections seront discutés.