Current-driven detection of terahertz radiation using a dual-grating-gate plasmonic detector

• Published in: Applied physics letters Vol. 104; no. 26
• Main Authors: Boubanga-Tombet, S., Tanimoto, Y., Satou, A., Suemitsu, T., Wang, Y., Minamide, H., Ito, H., Fateev, D. V., Popov, V. V., Otsuji, T.
• Format: Journal Article
• Language: English
• Published: Melville American Institute of Physics 30-06-2014
• Subjects: Applied physics; ASYMMETRY; CAVITY RESONATORS; CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; COOPERATIVES; Current voltage characteristics; CURRENTS; Dependence; DETECTION; ELECTRIC POTENTIAL; FIELD EFFECT TRANSISTORS; INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY; Low noise; NOISE; PLASMONS; Semiconductor devices; Sensors; THZ RANGE; Unit cell
• ISSN: 0003-6951; 1077-3118
• DOI: 10.1063/1.4886763

We report on the detection of terahertz radiation by an on-chip planar asymmetric plasmonic structure in the frequency region above one terahertz. The detector is based on a field-effect transistor that has a dual grating gate structure with an asymmetric unit cell, which provides a geometrical asymmetry within the structure. Biasing the detector with a dc source-to-drain current in the linear region of the current-voltage characteristic introduces an additional asymmetry (electrical asymmetry) that enhances the detector responsivity by more than one order of magnitude (by a factor of 20) as compared with the unbiased case due to the cooperative effect of the geometrical and electrical asymmetries. In addition to the responsivity enhancement, we report a relatively low noise equivalent power and a peculiar non-monotonic dependence of the responsivity on the frequency, which results from the multi-plasmonic-cavity structure of the device.