Frequency combs in quantum cascade lasers: An overview of modeling and experiments

Over the past decade, the demonstration of frequency combs has been reported in a wide range of quantum cascade lasers. These combs have huge potential in applications, including spectroscopy, sensing, imaging, and communication domains. In this perspective review, we explore the modeling and experimental state of the art on frequency combs in mid-infrared and terahertz quantum cascade lasers, 10 years since the first demonstrations that these devices can spontaneously generate combs.