Improved wall plug efficiency of a 1.9 THz quantum cascade laser by an automated design approach

Freeman, Joshua R.; Marshall, Owen; Beere, Harvey E.; Ritchie, David A.
November 2008
Applied Physics Letters;11/10/2008, Vol. 93 Issue 19, p191119
Academic Journal
We demonstrate an improvement in the wall plug efficiency in a bound-to-continuum quantum cascade laser operating below 2 THz. This was achieved by targeting one perceived weakness in a previous design, extraction from the lower laser state. This targeted improvement was made possible by employing an automated search algorithm to select a design giving rise to specified electronic states. The resulting laser design represents the highest wall plug efficiency below 2 THz and the lowest frequency devices to operate in the high-power single plasmon waveguide. The device displays a wall plug efficiency of 1.2% per facet, double the reference design.


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