Tuesday, October 4, 2016
Abstract-Patch antenna microcavity terahertz sources with enhanced emission
We study the emission properties of an electroluminescent THz frequency quantum cascade structure embedded in an array of patch double-metal microcavities. We show that high extraction efficiencies can be obtained by adjusting the active region thickness and array periodicity as well as high Purcell factors (up to 65), leading to an enhanced overall emitted power. Up to a 44-fold increase in power is experimentally observed in comparison with a reference device processed in conventional mesa geometry. Estimation of the Purcell factors using simulations and the theoretical extraction efficiency are in agreement with the observed power enhancement and show that, in these microcavities, the overall enhancement solely depends on the square of the total quality factor.