We have fabricated and characterized plasmonic terahertz detectors that integrate a voltage controlled planar barrier with a grating gated GaAs/AlGaAs high electron mobility transistor. These detectors exhibit a narrowband, tunable plasmonic response. Substantially increased responsivity is achieved by introducing an independently biased, narrow gate that produces a lateral potential barrier adjacent to the drain when biased to pinch-off. DC electrical characterization in conjunction with bias-dependent terahertz responsivity and time constant measurements indicate that a hot electron bolometric effect is the dominant response mechanism over a broad range of experimental conditions. The temperature dependence of the bolometric response is consistent with the energy relaxation time and absorption coefficient of a 2DEG. Rectification resulting from non-linear current-voltage characteristics also appears to contribute to the response. Additionally, we have begun investigating the operation of this device with the full grating gate biased to pinch-off to produce many detection elements in series.

Date Published: 9 February 2009
PDF: 8 pages
Proc. SPIE 7215, Terahertz Technology and Applications II, 721503 (9 February 2009); doi: 10.1117/12.809619

Published in SPIE Proceedings Vol. 7215:
Terahertz Technology and Applications II
Kurt J. Linden; Laurence P. Sadwick; Créidhe M. O'Sullivan, Editor(s)