A review of recent results of mid-infrared quantum cascade photonic devices operating under external optical control

The purpose of this article is to gather recent findings about the non-linear dynamics of distributed feedback quantum cascade lasers (QCLs), with a view on practical applications in a near future. As opposed to other semiconductor lasers, usually emitting in the visible or the near-infrared region, QCL technology takes advantage of intersubband transitions and quantum engineering to emit in the mid-infrared and far-infrared domain. This peculiarity and its physical consequences were long considered as a detrimental characteristic to generate non-linear dynamics under external optical control. However, we show that a wide diversity of phenomena, from high-dimensional chaos to giant pulses can be observed when the QCL is under external optical feedback or under optical injection and with a continuous current bias. Most of these phenomena have already been observed in other semiconductor lasers under optical feedback or under optical injection, which allows us to compare QCLs with their interband counterparts.

Automated summary

This article gathers recent findings on the non-linear dynamics of distributed feedback quantum cascade lasers (QCLs) and highlights their potential practical applications. Unlike other semiconductor lasers that emit in the visible or near-infrared region, QCL technology exploits intersubband transitions and quantum engineering to emit light in the mid-infrared and far-infrared domain. While it was previously thought that these characteristics hindered the generation of non-linear dynamics under external optical control, the article reveals that a wide range of phenomena, including high-dimensional chaos and giant pulses, can be observed in QCLs under external optical feedback or optical injection with a continuous current bias. Comparisons are drawn between QCLs and their interband counterparts, as similar phenomena have been observed in other semiconductor lasers.