Infrared pixel based on Seebeck nanoantennas

Bolometric arrays dominate in commercial terahertz and millimeter wave imagers. Bolometers tend to be slow and require an operating bias that increases the power budget. This paper presents first results on antenna-coupled thermo-electric junction detectors, a potentially attractive alternative to microbolometers. The nanoscale junctions have small thermal mass and can be much faster than bolometers. These junctions are heated by currents excited in spectrally-selective antennas and generate a voltage based on the Seebeck effect without any externally applied power. A pixel comprising a series array of antenna coupled junctions with peak response at 7.5 THz (40 µm wavelength) is designed and experimentally demonstrated. Responsivity of 5 MV/W, 500 Hz chopping frequency, and D* of 3.5 x 1010 Jones are demonstrated.