This thesis work is focused on the top metal grating applied to the Quantum Cascade Lasers operating in the mid-infrared range of the electromagnetic spectrum. Physic phenomena involved in such structure have been understood thank to simple models which have been powerful tools to design devices. Results are confirmed by numerical studies based on the more complex S-matrix formalism. This study leads to several realizations: o The processing of single-mode sources with a precise control of the wavelength. The originality of these devices comes from the low loss interaction of the electromagnetic field with the metal. This configuration enables the processing of room temperature continuous wave distributed feedback (DFB) QCLs. o The development of low divergence new devices, based on the combining of a first-order and a second order grating. o The demonstration of the capability of a QCL optically coupled to a high finesse cavity (OF-CEAS : Optical-Feedback Cavity-Enhanced Absorption Spectroscopy) for the high sensitive molecular spectroscopy. All these developments have demonstrated the high maturity level of the top metallic grating, well adapted to the quantum cascade laser for their integration in spectroscopic systems.
