Cascade Laser technologies - challenges for a broad adoption

Interband and Quantum Cascade Lasers (ICLs and QCLs) offer coherent and high-power radiation in the mid-infrared range, which is crucial for infrared countermeasures, high-resolution gas spectroscopy and chemical sensing. Due to many advantages, Cascade Lasers were expected to mature quickly and to settle in large volume applications. Especially the semiconductor nature of ICLs and QCLs gave hope to make this technology largely scalable and cheap, as it happened with LEDs and VCSELs in the past. Dynamic growth has not fully materialized in the last years. The price of lasers still remains high (around few thousand dollars per piece), and the potentially "killer" applications have not come yet. Cascade Lasers can be mainly found in niche applications. The reason for that lies both in the technical bottlenecks, but also in the market which has not been ready to implement CL technology. The customers were very conservative and there were many other competitive techniques to choose from. Now the perspectives for the adoption are brighter. All bottlenecks preventing the wider use of Cascade Laser technologies are deeply discussed in this study.