Gas recognition with terahertz time-domain spectroscopy and spectral catalog: a preliminary study

The ability to detect and recognise a variety of gases under certain environmental conditions has significant potential impact in many areas: from hazardous gas detection in the industrial domain to physical sciences in academia. Gas sensing has long received attention with microwave and infrared spectroscopy. With many molecular resonances occurring in the THz (T-ray) range leading to simple, unique spectral features, THz timedomain spectroscopy (TDS) shows promise as a tool for gas detection and recognition. This paper presents a preliminary study on real-time gas recognition with THz-TDS. In particular, a simple method is used that involves extracting line positions from gas species without a reference pulse and classifying them by means of the minimum Euclidean distance using the Submillimeter, Millimeter, and Microwave Spectral Line Catalog.