The goal of the Mir-THz research activity is to developp novel optoelectronic devices within the technologically under-developped part of the EM spectrum (Mid to Far infrared / λ ≈3 µm to 300 µm). To do so, we explore a solid state approach where we use the confined electronic transition within the conduction band of Quantum Wells (QW), the so-called intersubband transitions. These transitions are at the heart of various devices such as Quantum Cascade Lasers (QCL), Polaritonic light emitting diode (LED) and Quantum Well Infrared Photodetectors (QWIP).