A comprehensive review on the state of the art of THz quantum cascade lasers has been recently authored by Carlo Sirtori and Stefano Barbieri, members of our laboratory. The article has been published last September on Nature Photonics in a special issue with focus on “Advances in terahertz optics”.
This review, entitled “Wave engineering with THz quantum cascade lasers” discusses the concepts and techniques that have been implemented to control spectral and spatial beam properties of these semiconductor lasers with emission in the far infrared region. The invention of THz quantum cascade lasers dates back to 2002. Since then progress in this field has been inspired and helped by technologies developed in other frequency ranges, both conceptually (for example, light confinement in the microwave and near-infrared regions) and in terms of the technological performance offered by devices such as diode lasers and femtosecond lasers. The reader will find highlighted in the article three main research areas that have significantly contributed to the development of THz quantum cascade lasers: (i) 1D and 2D photonic-crystal structures for light confinement and extraction; (ii) intracavity nonlinear mixing between a THz wave and a near-infrared wave; (iii) the use of femtosecond-laser combs for frequency stabilization and coherent detection.
Figure:
Scheme of a THz laser with a saturable absorber on the front section to modulate the output power
Contact :
carlo.sirtori@univ-paris-diderot.fr
Référence:
Wave engineering with THz quantum cascade lasers.
C. Sirtori, S. Barbieri, and R. Colombelli Nature Photonics 7, 691 (2013).