Terahertz Wave Air Photonics: Terahertz Wave Generation and Detection With Laser-Induced Gas Plasma

Ultrabroadband, intense terahertz (THz) waves can be generated and detected using gaseous media as both the THz wave emitter and sensor, with a bandwidth covering the entire “THz gap” and well beyond. We review our most recent experimental and theoretical progress in THz generation, detection, and manipulation in laser-induced gas plasma. In the generation part, emphasis will be on the case with two-color excitation of gaseous media. Potential applications of these novel THz generation and detection techniques will also be discussed and proof-of-principle experiments are demonstrated.