Terahertz detection: approaches and trade-offs

Abstract

The development of faster and more sensitive detectors has been a major reason for the opening up of the THz spectral region. If only the amplitude of a THz wave is detected it is an incoherent or direct detector. When both the amplitude and phase are detected the detector is a coherent one. Coherent detection is not a direct process. In a heterodyne receiver, which is the most common coherent detector, detection is in two stages, with the incoming signal being 'mixed' with another signal, and it is the combination of both which is detected. In this lecture an overview will be presented about those incoherent and coherent detectors, which are used in many laboratories as weil as in space missions and other applications. The physics of the detection mechanism and major applications as weil as potential improvements will be presented. Finally, the trade-off between incoherent and coherent detection will be discussed.