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

S. Boubanga-Tombet^1,a), Y. Tanimoto¹, A. Satou¹, T. Suemitsu¹, Y. Wang²,H. Minamide², H. Ito², D. V. Fateev^3,4, V. V. Popov^3,4 and T. Otsuji¹
 HIDE AFFILIATIONS
1 Research Institute of Electrical Communication, Tohoku University, 2-1-1 Katahira, Aoba-Ku, Sendai 980-8577, Japan
2 RIKEN Sendai, 519-1399 Aramaki Aoba, Aoba-ku, Sendai 980-0845, Japan
3 Kotelnikov Institute of Radio Engineering and Electronics (Saratov Branch), 410019 Saratov, Russia
4 Saratov State University, 410012 Saratov, Russia
a) Author to whom correspondence should be addressed. Electronic mail: stephanealbon@hotmail.com
Appl. Phys. Lett. 104, 262104 (2014); http://dx.doi.org/10.1063/1.4886763

We report on the detection of terahertz radiation by an on-chip planar asymmetric plasmonicstructure 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.