The development of quantum cascade lasers (QCLs) operating at terahertz frequencies is proceeding at a rapid pace. Improvements have been obtained both in output power and operating temperatures, thanks to a combination of quantum design and fabrication methods, while the range of lasing frequencies has been extended below 1 THz. Distributed feedback devices have been fabricated with a variety of techniques for the purpose of achieving predictable single-mode emission, and external cavity set-ups have been implemented for tunability. THz QCLs have also become an important test-bed for new device concepts like non-periodic resonators, low volume microcavity lasers, and phase-matched non-linear devices that generate a THz signal on a near-IR carrier. Future developments will likely include optical circuits with photonic crystals, random lasers, new electro-mechanical tuning mechanisms, and possibly quantum dot lasers, further expanding the range of possible applications in many research areas.
Recent advances and future prospects of THz quantum cascade lasers
Tredicucci A.
2008
Abstract
The development of quantum cascade lasers (QCLs) operating at terahertz frequencies is proceeding at a rapid pace. Improvements have been obtained both in output power and operating temperatures, thanks to a combination of quantum design and fabrication methods, while the range of lasing frequencies has been extended below 1 THz. Distributed feedback devices have been fabricated with a variety of techniques for the purpose of achieving predictable single-mode emission, and external cavity set-ups have been implemented for tunability. THz QCLs have also become an important test-bed for new device concepts like non-periodic resonators, low volume microcavity lasers, and phase-matched non-linear devices that generate a THz signal on a near-IR carrier. Future developments will likely include optical circuits with photonic crystals, random lasers, new electro-mechanical tuning mechanisms, and possibly quantum dot lasers, further expanding the range of possible applications in many research areas.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.