Electrically switchable, two-color quantum cascade laser emitting at 1.39 and 2.3THz

Giacomo Scalari, Christoph Walther, Jérôme Faist, Harvey Beere, David Ritchie
2006 Applied Physics Letters  
A quantum cascade laser emitting at 1.39 and 2.3 THz is demonstrated. The structure is based on a large single quantum well and multiwavelength operation is obtained by selectively injecting carriers by resonant tunneling in the excited states of the well. A magnetic field applied perpendicularly to the layers increases the gain enabling laser action. Extremely low values of the threshold current density ͑below 30 A / cm 2 ͒ are observed for both wavelengths. A study of the dependence of the
more » ... ependence of the laser emission intensity as a function of the applied magnetic field is also presented.
doi:10.1063/1.2191407 fatcat:kmfowgnt2ncfjkavpl7nvqfasa