Experimental and theoretical investigation of terahertz optical‐beating detection by plasma waves in high electron mobility transistors

Abstract

AbstractA photomixed laser beam of two 1.55 mm cw lasers is used to obtain interband photoexcitation at the difference frequency and at room temperature in submicron gate‐length InAlAs/InGaAs transistors. Results show the clear excitation of plasma oscillation modes in the transistor channel. Fundamental plasma resonant frequency and its odd harmonics can be tuned with the applied gate voltage. Numerical simulations have also been performed using a hydrodynamic approach coupled to a pseudo‐2D Poisson equation. Numerical results are in qualitative agreement with experiments and confirm optical beating detection at terahertz frequencies. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)