GaN-based intersubband structures and mid-infrared quantum cascade lasers with heterogeneous cascades

C. Gmachl, H. M. Ng, D. L. Sivco, J. D. Heber, R. Colombelli, A. Soibel, F. Capasso, A. Y. Cho

Research output: Contribution to journalConference articlepeer-review

1 Scopus citations


We review two recent developments in the field of quantum cascade lasers. First, early studies of the GaN/AlGaN material system demonstrate the suitability of the latter for the communications wave-length range. Intersubband absorption measurements at wavelengths as short as λ≥ 1.35 μm are reported in multiple coupled quantum wells. An electron scattering time of few 100 fs between the subbands is obtained. Secondly, in InP-based quantum cascade lasers, the recent development of lasers with heterogeneous cascades, i.e. lasers with stacks of many intentionally dissimilar active regions interleaved with injectors is leading to novel concepts for multi-wavelength operation. We report broadband optical gain from 5 to 8 μm and Fabry-Perot laser action covering all wavelengths from 6 to 8 μm simultaneously in a single device.

Original languageEnglish (US)
Pages (from-to)125-132
Number of pages8
JournalInstitute of Physics Conference Series
StatePublished - 2003
Externally publishedYes
EventPhysics of Semiconductors 2002 - Proceedings of the 26th International Conference on the Physics of Semiconductors - Edinburgh, United Kingdom
Duration: Jul 29 2002Aug 2 2002

All Science Journal Classification (ASJC) codes

  • General Physics and Astronomy


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