The aim of the internship is to explore microcavity-coupled optoelectronic quantum devices which operate in the ultra-strong light-matter coupling regime. These devices are based on quantum well heterostructures integrated with multimode photonic microcavities and metamaterials. Such architectures can dramatically enhance light–matter interactions, enabling access to the ultra-strong coupling regime, which defines new frontiers in cavity quantum electrodynamics. In this regime, electronic excitations in quantum wells hybridize with optical modes of microcavities to form new coupled states—cavity polaritons—that can exhibit strikingly non-classical properties. Such properties can be uncovered by electrical transport measurements or through the non-linear optical conversion which takes place under strong coherent pump. As an intern, the candidate will characterize optoelectronic devices that have been already fabricated in clean room. She/he will thus acquire advanced training in infrared spectroscopy and electrical measurements of quantum devices, including in cryogenic conditions. The internship can be followed by a PhD project specifically focused on non-linear optical effects in such devices. The PhD funding is available through an ANR project.