Field-effect transistors as electrically controllable nonlinear rectifiers for the characterization of terahertz pulses

Alvydas Lisauskas,Sylvain Massabeau,Martin Mittendorff,Hartmut G Roskos,Kęstutis Ikamas,Jonas Matukas,Juliette Mangeney,Maris Bauer,Dovilė Čibiraitė,Viktor Krozer,Stephan Winnerl

doi:10.1063/1.5011392

Abstract

We propose to exploit rectification in field-effect transistors as an electrically controllable higher-order nonlinear phenomenon for the convenient monitoring of the temporal characteristics of THz pulses, for example, by autocorrelation measurements. This option arises because of the existence of a gate-bias-controlled super-linear response at sub-threshold operation conditions when the devices are subjected to THz radiation. We present measurements for different antenna-coupled transistor-based THz detectors (TeraFETs) employing (i) AlGaN/GaN high-electron-mobility and (ii) silicon CMOS field-effect transistors and show that the super-linear behavior in the sub-threshold bias regime is a universal phenomenon to be expected if the amplitude of the high-frequency voltage oscillations exceeds the thermal voltage. The effect is also employed as a tool for the direct determination of the speed of the intrinsic TeraFET response which allows us to avoid limitations set by the read-out circuitry. In particular, we show that the build-up time of the intrinsic rectification signal of a patch-antenna-coupled CMOS detector changes from 20 ps in the deep sub-threshold voltage regime to below 12 ps in the vicinity of the threshold voltage.

Highlights

Utilization of sources generating short optical pulses requires techniques for the monitoring of the temporal characteristics of the pulses
transmission line (TL)-based theories have been modified to account for the nature of electron screening at comparatively large wavevectors k for kd ≥ 1 with d being the separation between the gate electrode and the channel.[10,11]
TeraFETs have been employed for the detection ofnanosecond THz pulses taking advantage of the fact that the build-up time of their response is in the range of only ten or a few tens of picoseconds.[14,15,16]

Summary

Introduction

Utilization of sources generating short optical pulses requires techniques for the monitoring of the temporal characteristics of the pulses. We experimentally investigate this super-linear response at sub-threshold bias conditions and find it for both AlGaN/GaN high-electron-mobility transistors and silicon CMOS FETs subjected to THz pulses.

Results

Conclusion