International audienceInAs quantum-dot (QD) laser structures are grown on (113)B-oriented InP substrate by gas-source molecular-beam epitaxy. Following an optimized growth procedure, a high density of 1.1×1011 cm−2 of uniformly sized QDs is achieved. Broad-area lasers containing three stacked QD layers have been realized and tested. Laser emission on the ground-state transition (λ = 1.59 μm) is obtained at room temperature (RT), at a threshold current density as low as 190 A/cm2. Ground-state modal gain and transparency current density is measured to be 7 cm−1 and 23 A/cm2 per dot layer. Ground-state laser emission is also demonstrated from low temperature (100 K, Jth = 33 A/cm2) to high temperature (350 K), exhibiting an insensitive threshold in the [100, 170] K range, and a 55 K characteristic temperature at RT

Polyurethane nanocomposites with high content of red NIR luminescent transition metal clusters are presented. The gas permeability of the hybrid material is controlled by adjusting the hard/soft segment ratio of the organic matrix structure leading to a drastic and reversible enhancement of cluster luminescence depending on the molecular oxygen concentration in its surrounding atmosphere.

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