1.55 µm InAs/GaAs Quantum Dots and High Repetition Rate Quantum Dot SESAM Mode-locked Laser

High pulse repetition rate (≥10 GHz) diode-pumped solid-state lasers, modelocked using semiconductor saturable absorber mirrors (SESAMs) are emerging as an enabling technology for high data rate coherent communication systems owing to their low noise and pulse-to-pulse optical phase-coherence. Quantum dot (QD) based SESAMs offer potential advantages to such laser systems in terms of reduced saturation fluence, broader bandwidth, and wavelength flexibility. Here, we describe the development of an epitaxial process for the realization of high optical quality 1.55 µm In(Ga)As QDs on GaAs substrates, their incorporation into a SESAM, and the realization of the first 10 GHz repetition rate QD-SESAM modelocked laser at 1.55 µm, exhibiting ∼2 ps pulse width from an Er-doped glass oscillator (ERGO). With a high areal dot density and strong light emission, this QD structure is a very promising candidate for many other applications, such as laser diodes, optical amplifiers, non-linear and photonic crystal based devices

EELS analysis of InxGa1-xAsySb1-y nanostructures

International audienceThis work is focused on the analysis by TEM analytical techniques of InAs-GaAs-Sb nanostructure

Graphene-Based Metal-Free Catalysis

This chapter focuses on the use of doped carbon nanomaterials in catalysis. The availability of carbon nanotubes in the ‘90s and graphene about 10Â years later, prompted the development of fundamental research and novel nanotechnologies. We discuss this topic from a point of view that links fundamental surface science to the field of catalysis, in order to present the state of the art. We describe scientific questions that material scientists have faced during these last decades, in particular, we concentrate on the debate over the role that the different nitrogen configurations in the graphene lattice can play in certain catalytic processes