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We demonstrate the experimental measurements of the turn-on delay in InAs-and InP-based quantum cascade lasers operating under pulsed electrical pumping with non-zero rise time. We report the unexpected delay time dependence on the pumping current density, that does not agree with available theoretical predictions. Performed numerical simulation of the model based on rate equations is only in qualitative, but not quantitative, agreement with our observations.

Optomechanical coupling between cantilever of the atomic force microscope (AFM) and a semiconductor laser was studied. When an AFM cantilever is oriented parallel to the surface of the emitting semiconductor laser, the system forms an optomechanical resonator. The optomechanical coupling due to photothermal effect was shown in room conditions. By optomechanical cooling the effective temperature of Si3N4 cantilever was reduced down to 80 K. Amplitude-to-phase conversion in the studied cavity was demonstrated.

The molecular beam epitaxy growth of strained (Ga, In)Sb/GaSb quantum wells is investigated. In a narrow range of growth conditions, (Ga, In)Sb quantum well structures exhibiting excellent structural properties as well as intense and narrow photoluminescence transitions are obtained. Stimulated emission at 1.98 m is observed at room temperature from laser diodes with strained quantum wells as the active zone. The lasers exhibit threshold current densities as low as 280 A and a characteristic temperature of 75 K.

GaSb-based heterostructures with strained-layer (x = 0.26 or x = 0.35) single quantum wells and cladding layers were grown by molecular beam epitaxy. The thickness of the GaInSb well was varied from 3.0 to 14.5 nm. Intense room-temperature electroluminescence was observed from mesa diodes with peak emission wavelengths in the spectral range. The dependence of emission energy on well thickness is consistent with the predictions obtained by an effective mass treatment assuming a rectangular type I quantum well and a conduction band offset .

Low-threshold laser emission at room temperature of a GaSb-based quantum well structure is reported in this paper. The optical and electrical confinement of the structure have been improved by inserting an aluminium oxide layer obtained by wet oxidation of AlAs in the upper confinement layer. The strains between the oxide layer and the contiguous layers (GaAs and GaSb) are compensated by an AlAs/GaAs superlattice. The resulting morphology of the oxidized AlAs layers is presented.

InyGa1-yAs1-xBix layers on InP:Fe (100) substrates have been grown by molecular beam epitaxy. Up to 7% of Bi incorporation has been confirmed by optical and structural analyses of grown samples. Photoluminescence signals at wavelengths up to 3 µm have been observed, implying InyGa1-yAs1-xBix to be a prospective material for mid-infrared applications. A weak band-gap temperature sensitivity of Bi-containing InGaAs has been evaluated from optical absorption measurements.

We study a Quantum Hot Electron Transistor, an original transistor made of InAs/AlSb heterostructures with high speed intrinsic transport. It is a unipolar vertical transport device, based on the concept of hot electron transistor. Devices using different heterostructure designs have been grown, processed and characterized. Both resonant and parasitic transport of electrons is studied by mean of the static output characteristics of the transistors. We demonstrated that a key parameter is the design and thickness of the collector barrier. For 15nm-thin barriers, we obtained static current gain of 5 associated to a base transit time of 140 fs.