JILA researchers have developed a laser-based source of terahertz radiation that is unusually efficient and less prone to damage than similar systems. The technology might be useful in applications such as detecting trace gases or imaging weapons in security screening.
JILA instrument for generating terahertz radiation. Ultrafast pulses of near-infrared laser light enter through the lens at left, striking a semiconductor wafer studded with electrodes (transparent square barely visible under the white box connected to orange wires) bathed in an oscillating electric field. The light dislodges electrons, which accelerate in the electric field and emit waves of terahertz radiation. At right is a close-up of the electron source.
JILA is a joint institute of the National Institute of Standards and Technology (NIST) and the University of Colorado at Boulder.