Field Effect Transistors for Terahertz Detection: Physics and First Imaging Applications

Resonant frequencies of the two-dimensional plasma in FETs increase with the reduction of the channel dimensions and can reach the THz range for sub-micron gate lengths. Nonlinear properties of the electron plasma in the transistor channel can be used for the detection and mixing of THz frequencies. At cryogenic temperatures resonant and gate voltage tunable detection related to plasma waves resonances, is observed. At room temperature, when plasma oscillations are overdamped, the FET can operate as an efficient broadband THz detector. We present the main theoretical and experimental results on THz detection by FETs in the context of their possible application for THz imaging.Comment: 22 pages, 12 figures, review pape

Charge carrier transport properties in single-walled carbon nanotube fibers Proc.

International audienc

The response rate of room temperature terahertz InGaAs-based bow-tie detector with broken symmetry

A bow-tie InGaAs with broken symmetry has been designed for terahertz detection at room temperature. An active part of the detector consists of a two-dimensional electron gas which is heated non-uniformly with incident radiation. Main detector performances are operation in a passive scheme, flat frequency response up to 1 THz, the voltage sensitivity of about 5 V/W, the noise equivalent power of roughly 10 nW/Hz(exp 1/2), and the response time less then 7 ns

Heterodyne and spectroscopic room temperature terahertz imaging using InGaAs bow-tie diodes

Heterodyne and spectroscopic terahertz imaging using InGaAs bow-tie diodes are presented and discussed. The improvement of the dynamic range and noise equivalent power by heterodyning is demonstrated. It is shown that InGaAs-based bow-tie diodes are well suited for spectroscopic room temperature imaging within the range of 0.58-2.52 THz. The devices implementation in real-time imaging system is considered as well

Some properties of a room temperature THz detection array

Detection peculiarities of an un-cooled (room temperature) 8×8 pixel array designed to image broadband THz radiation were investigated. Each pixel consists of a thin conductive film absorber on a dielectric membrane with thermopile temperature readout. It was designed and tested for four combinations of two different types of absorber and thermopile materials. The photo-response profile, determined by scanning the pixels through the focus of a THz laser beam, was wider than expected from a 2-D convolution of the Gaussian beam and the absorber surface. Also the time response did depend on the position of the beam relative to the pixel. Simulations show that those properties are due to the fact that also the thermopiles absorb THz radiation. For the best composition of absorber and thermopile, the responsivity, the noise equivalent power, and the bandwidth were estimated to be of 28 V/W, 5×10-9 W/Hz1/2 and 50 Hz, respectively.Electronic Instrumentation LaboratoryElectrical Engineering, Mathematics and Computer Scienc

Antenna model for wire lasers

Kavli Institute of Nanoscience DelftApplied Science