Diagnosis of atmospheric pressure plasmas by using terahertz time-domain spectroscopy

A parallel-plate atmospheric plasma generator has been built with discharge electrodes that also serve as a non-dispersive terahertz (THz) waveguide for plasma diagnostics based on THz time-domain spectroscopy. It has been confirmed that, in the system, a uniform glow-like atmospheric pressure plasma is generated and THz waves propagate as designed.