Abstract: A terahertz scanner for detecting irregularities, such as chemical or structural variations, in a sample and methods of use thereof are described. The described terahertz scanner and algorithms allow for direct, high-sensitivity, high-throughput, and non-invasive detection of irregularities that range from chemical contaminant to material defects in a variety of substrates and settings.

Abstract: A terahertz scanner for detecting irregularities, such as chemical or structural variations, in a sample and methods of use thereof are described. The described terahertz scanner and algorithms allow for direct, high-sensitivity, high-throughput, and non-invasive detection of irregularities that range from chemical contaminant to material defects in a variety of substrates and settings.

Abstract: Methods and systems for determining water status in plant tissue are provided. A number of systems are capable of using terahertz signals to generate signals measuring total water content in plant tissue, including plant leaves. Using these signals, methods are capable of determining water status variables, including water mass per leaf area, relative water content, and leaf water potential, which can aid in agricultural, ecological, and environmental health, such as dehydration and droughst stress of plants.

Abstract: A photoconductive device that includes a semiconductor substrate, an antenna assembly, and a photoconductive assembly with one or more plasmonic contact electrodes. The photoconductive assembly can be provided with plasmonic contact electrodes that are arranged on the semiconductor substrate in a manner that improves the quantum efficiency of the photoconductive device by plasmonically enhancing the pump absorption into the photo-absorbing regions of semiconductor substrate. In one exemplary embodiment, the photoconductive device is arranged as a photoconductive source and is pumped at telecom pump wavelengths (e.g., 1.0-1.6 ?m) and produces milliwatt-range power levels in the terahertz (THz) frequency range.