An antimonide-based InAs/GaSb/InSb short-period superlattice (SPSL) laser diode on GaSb substrate for mid-infrared emission has been modeled by an accurate eight-band k.p model. By using a realistic graded and asymmetric interface profile, calculated energy gap between the electron and heavy-hole miniband shows good agreement with our experimental data. Optical gain and threshold current density are then presented and compared with experimental results of SPSL laser diodes operating in pulsed regime. Analysis of the optical performances obtained at room temperature is made.

The electronic band structure and optical gain of an InAs/GaSb/InSb short-period superlattice laser diode on a GaSb substrate are numerically investigated with an accurate 8 × 8 k.p model. Using a realistic graded and asymmetric interface profile, we obtain a reasonable agreement on band gap energy with our experimental data extracted from laser emissions performed on the laser diode. The optical performance in terms of optical gain is then calculated for the laser structure and we demonstrate the utility of interface design to model short-period superlattice structures.

We use a standard 8 × 8 envelope-function approximation (EFA) formalism taking into account the effect of anisotropic and other interface (IF) interactions to investigate the electronic and optical properties of short-period superlattice laser structures (InAs/GaSb/InSb)×N grown on a GaSb substrate. We find that the band gaps numerically calculated at different temperatures give a good fitting with the experimental data confirming the model used. The calculated modal gain demonstrates that it is possible to achieve lasing operation at room temperature for N > 12 and for a reasonable total optical loss α t = 25 cm −1 . Therefore, the 8 × 8 EFA formalism with IF design serves as a tool to model the optoelectronic properties of InAs/GaSb/InSb SPSLs.

No abstract

L’axe des incisives inférieures occupe une position «clé» dans différentes analyses céphalométriques. Cependant, les critiques se rapportant à la téléradiographie et aux repères céphalométriques (point, ligne, angle) sont nombreuses. Les normes publiées et les standards céphalométriques recommandés pour le positionnement optimal des incisives ne peuvent être utilisés que comme des lignes-guides cliniques. Le repositionnement des incisives en vue d’une esthétique faciale et d’une fonction optimales requiert la prise en compte des tissus durs et des tissus mous de la face, du profil, de la dynamique musculaire et de la croissance faciale. L’objectif de ce travail est de proposer une nouvelle approche du repositionnement incisif, illustrée par des cas cliniques, en tenant compte du contexte osseux, des facteurs parodontaux, fonctionnels et esthétiques.