Two novel experimental schemes for terahertz tomography

In this contribution, we present two novel and compact terahertz tomography spectroscopy concepts. First, we exploit continuous-wave (CW) terahertz radiation generation and phase-sensitive detection in the same single photoconductive antenna (PCA), a homodyne self-mixing detection approach and apply it within a 2D terahertz tomography imaging application where we reconstruct the two-dimensional image of a hollow-core Teflon cylinder filled with α-lactose as a proof-of-concept demonstration. Second, we realize a single-pixel tomography scheme where 2D tomographic spatial information is achieved by spatially-resolved photodoping of a high-resistivity silicon wafer plate giving rise to fast transverse single-pixel information (via a digital micro mirror device (DMD)) with the subsequent rotation of the object for tomography. Both concepts offer a significantly reduced complexity and consequently lower cost of the terahertz spectroscopy set-up and their THz performance will be discussed and compared.