Frequency-agile terahertz-wave spectrometer for high-resolution gas sensing

Abstract

A tabletop, frequency-agile terahertz-wave spectrometer was developed based on an injection-seeded terahertz-wave parametric generator. High-resolution (<100MHz) spectra of polar gases can be measured in a wide frequency region (0.6–2.4THz) within a short time (several minutes) with this spectrometer. To demonstrate the potential of this system, the authors performed real-time detection of the absorption line due to rotational transitions of the water molecule and determined their pressure-broadening coefficient.