Les lasers à cascade quantique : l’accès au moyen infrarouge

L'analogie, un moyen de croiser les contraintes et les paradigmes

The paper proposes a technique to acquire morphological constructional (derivational) relations from dictionaries of synonyms in order to create morphological databases semi-automatically. It exploites the paradigmatic structure of the lexicons in several ways. The technique is based on the discovery of analogical (morpho-synonymic) quadruplets where semantic contraints defined as synonymic rel...

Temperature Effect on THz Quantum Cascade Lasers

A simple semi-phenomenological model, which accurately predicts the dependence of thresholdcurrent for temperature of Resonant-phonon three well quantum cascade laser based on verticaltransitions is offered. We found that, the longitude optical phonon scattering of thermally excitedelectrons is the most important limiting factor for thermal performance of high frequency THz QCLs.In low frequenc...

La médecine à Montpellier, Vol. 1, Le Moyen Âge

Design Optimization for 4.1-THZ Quantum Cascade Lasers

We present an optimized design for GaAs/AlGaAs quantum cascade lasers operating at ‎‎4.1THz. This was based on a three-well active module with diagonal radiative transition. This ‎was performed by modifying the existing model structure, to reduce the parasitic anticrossings ‎‎(leakage currents) as well as the optical gain linewidth. While the gain FWHM was reduced by ‎more than 50% the gain pea...

Structuration d’un peuplement hétérogène au moyen d’éclaircies locales

Local rules optimization in a mixed stand. We present a treemarking model based on local rules, which optimizes the structure of the stand. The stand is divided into plots with constant number of trees. A plot is described by the number of trees in diameter classes for each species. These variables are random variables and their probability law are modeled by a mixture of multinomial distributi...