Terahertz sources and detectors for security applications

Paper in proceeding, 2006

We will present recent results on terahertz source and detector technology, (0.1-10 THz), for safety and secu-rity applications. The development of terahertz technology remains very challenging. This is primarily because this frequency band lies in the transition between classical microwave electronics and photonics. For example, traditional transistor based monolithic integrated circuits does not work well above 150 GHz. Similarly, semiconductor lasers used in the IR (and visible) region does not work well below 2 THz and still need cooling at these long wavelengths (ca 100µm). Today, high power and compact multipliers are the most efficient solution for the frequency range 0.2-2THz (THz-gap). The Heterostructure Barrier Varactor (HBV) diode was invented 1989 at Chalmers and is used in high order frequency multiplier circuits (x3, x5). We have demonstrated significant output power in the millimeter wave region (0.2W @ 114GHz) and highly efficient HBV circuits up to 500GHz. Progress and development of high power HBV sources for the terahertz fre-quency range will be discussed and presented. Furthermore, research and development of direct and hetero-dyne detector technology, both Schottky diodes and Hot Electron Bolometers (HEB), for use in imaging (THz-camera) applications will be presented. These technologies are crucial for development of new THz-sensor systems.