Nonlinear Photonics in Mid-infrared Quantum Cascade Lasers

This thesis presents the first comprehensive analysis of quantum cascade laser nonlinear dynamics and includes the first observation of a temporal chaotic behavior in quantum cascade lasers. It also provides the first analysis of optical instabilities in the mid-infrared range. Mid-infrared quantum cascade lasers are unipolar semiconductor lasers, which have become widely used in applications such as gas spectroscopy, free-space communications or optical countermeasures. Applying external perturbations such as optical feedback or optical injection leads to a strong modification of the quantum cascade laser properties. Optical feedback impacts the static properties of mid-infrared Fabry-Perot and distributed feedback quantum cascade lasers, inducing power increase; threshold reduction; modification of the optical spectrum, which can become either single- or multimode; and enhanced beam quality in broad-area transverse multimode lasers. It also leads to a different dynamical behavior, and a quantum cascade laser subject to optical feedback can oscillate periodically or even become chaotic.  A quantum cascade laser under external control could therefore be a source with enhanced properties for the usual mid-infrared applications, but could also address new applications such as tunable photonic oscillators, extreme events generators, chaotic Light Detection and Ranging (LIDAR), chaos-based secured communications or unpredictable countermeasures.

Louise Jumpertz graduated from Institut d'Optique Graduate School (France) in 2013 with an Engineering degree and a Master of research in optics. She graduated with a PhD in Electronics and Communications from Telecom ParisTech (France) in collaboration with the company mirSense in November 2016. She is currently working as a post-doctoral researcher at the French-German Research Institute of Saint-Louis. Her research interests are laser physics at various wavelengths (visible, near- and mid-infrared) and nonlinear optics.