⮞ Département SP ⮞ Thématiques de recherche⮞ Activités « Communications Optiques »
Because of our unrestrained use of digital technologies, data centers are overloading electrical grids and demanding huge amounts of water and energy. Faced with our inability to envision new paradigms for our societies, researchers work on energy-efficient and high bandwidth solutions meeting data centers bandwidth needs.
In this work, LAAS-CNRS has developed a new surface emission electro-optic transducer. This technology, the same as the vertical-cavity surface-emitting laser (VCSEL) one, gives a good energy-efficiency / cost / bandwidth trade-off. VCSEL dynamic properties is however intrinsically limited by its direct carrier modulation. Surface-normal modulator addresses this issue while being compatible with a monolithic integration with a VCSEL (used in this case as a continuous laser source), and with a 2D matrix integration. Fabricated on an AlGaAs platform for modulation in the 850 nm spectral window, a modulation bandwidth of 33 GHz has been measured on the device which is at the state of the art in this spectral window.
In accordance with the heart of the activities in optical telecommunication at institut Foton, and using experimental tools of PERSYST platform, our role was to study this on-chip device for future optical networks. After static characterizations in order to grasp the physical mechanisms under play (a-b), dynamic characterizations gave an idea of its performances close to real conditions at 50 Gbit/s at different wavelengths and transmission distances (c-d).
Collaborations
Projets financés
- EAM-VCSEL (2020-2024), développement de sources Tb/s bas-coût, basse consommation pour les communications optiques courtes distance. Financement ANR (Appel générique)
- Si-VCSEL (2026-2030), développement de sources Tb/s bas-coût, basse consommation pour les communications optiques courtes distance sur plateforme matériau plus durable. Financement ANR (appel générique).
Contact: for the characterisations, for the fabrication
Publications associés
M. Gay, et al. “50 Gbit/s Transmission at 850 nm with a Surface-Normal Electroabsorption Modulator” Photonics West OPTO, SPIE, Jan 2025, San Francisco, United States, hal-04768548
C. Viallon , et al., “50 Gbit/s AlGaAs Vertical-Cavity Electro-Absorption Modulator for Short-Wavelength Optical Communication Over 2 km SMF”, Journal Selected Topics Quantum Electronics, 2026, submitted.