Description du sujet de thèse

The goal of the project is to develop non-linear devices based on intersubband transitions in III-V semiconductor heterostructures. These are optical or electronic nonlinearities. In the case of optical non-linearities, the target spectral range is mid-infrared (3-12 microns).
The activity will be based on intersubband transitions between electronic states confined in semiconductor quantum wells (QW). Such transitions are the key elements of quantum devices in the mid-infrared (quantum cascade lasers, quantum well infrared detectors). They are suitable for exploring new phenomena where cavity electrodynamics play a fundamental role.
A first objective is to study and develop a device which behaves like a detector when it is subjected to infrared light, but – in the absence of photons and at low temperature – its electronic transport properties are affected by the strength of the light-matter coupling. The dual behavior is made possible by operating in the ultra-strong light-matter coupling regime. This regime can be achieved when a semiconductor device is integrated into a highly confining optical microcavity.
The second objective concerns optical nonlinearities. This involves developing semiconductor saturable absorption mirrors (SESAMs) for the mid-infrared spectral range so that they can be tuned in frequency by the application of an external voltage. These mirrors will then be used in conjunction with interband cascade lasers, or fiber lasers in the mid-infrared spectral range.

Contexte de travail

Work will take place at the Center for Nanosciences and Nanotechnology, on the Plateau de Saclay.
The Center for Nanosciences and Nanotechnologies (C2N) is a joint research unit of the CNRS and the University of Paris Saclay and the University of Paris Cité. The C2N, with around 410 staff, is located in Ile de France in Palaiseau (91) in the heart of the Paris Saclay campus.
The C2N hosts four scientific departments (photonics, materials, nanoelectronics, nanobiofluidic microsystems). This position is within the photonics department. This position requires access to the clean room.

Le poste se situe dans un secteur relevant de la protection du potentiel scientifique et technique (PPST), et nécessite donc, conformément à la réglementation, que votre arrivée soit autorisée par l'autorité compétente du MESR.

Contraintes et risques

N/A