Light emitting diodes (LEDs) can be coupled to optical fibers and used in telecommunication applications. Compared to laser diodes, the coupling is usually small, due to the isotropic emission of the source, combined with the large refractive index difference between the semiconductor and the outside medium. However, it is possible to greatly enhance the optical extraction of a planar LED by placing the source inside a microcavity which optical thickness is close to the wavelength of the emitted light. Some elementary design rules of a microcavity light emitting diode (MCLED) are explained here, and are illustrated on a real GaAs/AlxGa1−xAs device emitting at 880 nm. The surface external quantum efficiency of this MCLED reaches 14% into air and 20.6% with an encapsulation into an epoxy lens. These values are about 10 times larger than for a usual LED and are in good agreement with theoretical values, calculated with a plane waves model.
Les diodes électroluminescentes (LEDs) peuvent être couplées à des fibres optiques et utilisées pour des applications en télécommunications. Ce couplage est généralement assez faible, en comparaison de celui qui est obtenu avec des diodes laser. Ceci est dû principalement à l'émission isotropique de la source, combinée à la grande différence d'indice de réfraction entre le semiconducteur et le milieu extérieur. Cependant, l'extraction optique d'une LED planaire peut être largement augmentée si la source est placée à l'intérieur d'une microcavité dont l'épaisseur est proche de la longueur d'onde de la lumière émise. Nous expliquons ici quelques règles fondamentales de conception d'une LED à microcavité (MCLED), et nous les illustrons avec l'exemple d'un composant réel en GaAs/AlxGa1−xAs, émettant à 880 nm. Le rendement quantique externe de cette MCLED atteint 14 % pour une emission dans l'air et 20,6 % avec une encapsulation dans une lentille en époxy. Ces valeurs sont près de dix fois supérieures à celles d'une LED standard, et sont en bon accord avec les valeurs théoriques, calculées à l'aide d'un modèle d'ondes planes.
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Mot clés : diode électroluminescente, microcavité, brillance, Fabry–Pérot, semiconducteurs
Daniel Ochoa 1; Romuald Houdré 1; Marc Ilegems 1; Christian Hanke 2; Bernt Borchert 2
@article{CRPHYS_2002__3_1_3_0, author = {Daniel Ochoa and Romuald Houdr\'e and Marc Ilegems and Christian Hanke and Bernt Borchert}, title = {Microcavity light emitting diodes as efficient planar light emitters for telecommunication applications}, journal = {Comptes Rendus. Physique}, pages = {3--14}, publisher = {Elsevier}, volume = {3}, number = {1}, year = {2002}, doi = {10.1016/S1631-0705(02)01291-4}, language = {en}, }
TY - JOUR AU - Daniel Ochoa AU - Romuald Houdré AU - Marc Ilegems AU - Christian Hanke AU - Bernt Borchert TI - Microcavity light emitting diodes as efficient planar light emitters for telecommunication applications JO - Comptes Rendus. Physique PY - 2002 SP - 3 EP - 14 VL - 3 IS - 1 PB - Elsevier DO - 10.1016/S1631-0705(02)01291-4 LA - en ID - CRPHYS_2002__3_1_3_0 ER -
%0 Journal Article %A Daniel Ochoa %A Romuald Houdré %A Marc Ilegems %A Christian Hanke %A Bernt Borchert %T Microcavity light emitting diodes as efficient planar light emitters for telecommunication applications %J Comptes Rendus. Physique %D 2002 %P 3-14 %V 3 %N 1 %I Elsevier %R 10.1016/S1631-0705(02)01291-4 %G en %F CRPHYS_2002__3_1_3_0
Daniel Ochoa; Romuald Houdré; Marc Ilegems; Christian Hanke; Bernt Borchert. Microcavity light emitting diodes as efficient planar light emitters for telecommunication applications. Comptes Rendus. Physique, Volume 3 (2002) no. 1, pp. 3-14. doi : 10.1016/S1631-0705(02)01291-4. https://comptes-rendus.academie-sciences.fr/physique/articles/10.1016/S1631-0705(02)01291-4/
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