Summary: IEEE PHOTONICS TECHNOLOGY LETTERS, VOL. 18, NO. 18, SEPTEMBER 15, 2006 1925
Far-Infrared Spectrum Analysis Using Plasmon
Modes in a Quantum-Well Transistor
E. A. Shaner, A. D. Grine, M. C. Wanke, Mark Lee, J. L. Reno, and S. J. Allen
Abstract--Excitation of resonant plasmon modes by far-infrared
(FIR) radiation in a quantum-well transistor is used to analyze
the spectral content of FIR illumination at frequencies between
0.58 and 0.99 THz. A split grating gate design that allows localized
pinch-off of the transistor channel greatly enhances FIR response
and allows completely electrical tuning of the plasmon resonance,
enabling broadband FIR spectrum analysis without moving parts.
A voltage ramp applied to the gate can generate a spectrum at video
rate.
Index Terms--Far infrared, submillimeter-wave detectors,
submillimeter-wave spectroscopy, terahertz.
I. INTRODUCTION
THE far-infrared (FIR) spectrum, roughly 0.1­10 THz, con-
tains the resonance signatures of many molecules and ma-
terials [1], [2]. These signatures arise from quantized rotational
modes (in vapors) and lattice vibrations (in solids), which can

Source: Allen, S. James - Department of Physics, University of California at Santa Barbara

Collections: Physics; Materials Science