Quantum Cascade lasers in 2025: sensing applications, new methods and latest developments (Conference Presentation)

We recap the history and evolution of Quantum Cascade Lasers, from their discovery 30 years ago to current applications. On the one hand the workhorse DFB chip has seen dramatic improvements in power consumption which has allowed integration of CW devices in standardized housing. This has allowed multiple operation modes to be used. As each method comes with tradeoffs in terms of peak power, tuning range and tuning speed, we will discuss how to select the ideal method depending on the use case. On the other hand, we will also describe how different modern QCL products can be used to address some of the harmful trade-offs required by simple DFB devices.