The present invention relates to a process for fabricating light-emitting device. More particularly, the aim of the invention is to allow the fabricating of light emitters with improved efficiency by using artificial materials, enabling antireflection or high-reflectivity treatments to be carried out. For this purpose, subwavelength structures are etched on one of the ends of an emissive cavity, enabling external face to be controlled. The invention applies to any light emitter, and therefore notably to lasers and more particularly still to QCLs (quantum cascade lasers). Moreover, the fabrication process according to the invention is preferably a wafer-scale process.