THz imaging with broadband thermal sources

We developed a THz imaging system based on a broadband thermal source (at 500°C) and an asymmetric semiconductor nanochannel, the self-switching nanodiode (SSD), as a room-temperature detector. The maximum resolution was better than 0.5 mm full width at half maximum. The radiation was coupled to the SSD through a microantenna, whose geometry determined the frequency bandwidth of the system. While not as accurate as coherent imaging, the compactness, low-cost, and flexibility make this system attractive for a large range of applications in medical imaging and industrial quality control.