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Electronically Tunable THz Mirrors


NSF funded researchers at Rensselaer Polytechnic Institute demonstrated, for the first time, nearly perfect electrically tunable THz mirrors based on plasmonic resonance in AlGaN/GaN two-dimensional electron gas. IGERT (Integrative Graduate Education and Research Traineeship) co-PI Professor Shur’s group supported by the NSF through the IGERT demonstrated that oscillations of electron density (called plasma waves) in two-dimensional electron gas in large (several square mm) structures with thousands of submicron gate fingers enable resonant reflection of THz radiation at frequency tunable by the voltage applied to the gate fingers.

Address Goals

The terahertz (THz) frequency band of the electromagnetic radiation is important for various spectroscopic applications, since unique vibration, rotational, and translational responses of materials belong to the THz band [2, 3]. These unique electronically tunable THz mirrors will enable ultra high power THz sources greatly expanding application of THz technology 3.

1 A.V. Muravjov, D.B. Veksler*, X. Hu, R. Gaska, N. Pala, H. Saxena, R.E. Peale, M.S. Shur, Resonant terahertz absorption by plasmons in grating-gate GaN, HEMT (high electron mobility transistor) structures, OSA Proceedings (2009), accepted.

2 M. K. Choi, A. Bettermann, and D. W. van der Wiede, “Potential for detection of explosive and biological hazards with electronic terahertz systems”, Phil. Trans. R. Soc. Lond. A, 362, pp. 337-349 (2004). 3 F. De Lucia, “Spectroscopy in the terahertz spectral region”, in Sensing With Terahertz Radiation, D. Mittleman, Ed. Springer Verlag, Berlin, pp. 39-115 (2003).