Abstract

In the presentation, we successfully demonstrate the feasibility of in situ and remote chemical detection through the use of a reflective terahertz (THz) fiber-scan imaging system to trace the dynamic generation of a compound during a chemical reaction and concurrently to map out the spatial distribution of the chemical product. The reflective THz fiber-scan system is demonstrated at 0.4 THz emitted from a continuous THz wave source, and a simple Teflon pipe with low THz transmitting and bending loss [1–3] is used as a sensing and image scanning arm. The bending capability of the reflective THz–pipe–scan system is experimentally characterized and proven by identifying a tablet array through its pipe-scanned THz image. The chemical sensing/imaging capability of the system is validated through remote measurement of the reflected THz power from a chemical product, ammonium chloride (NH₄Cl) aerosols, which is dynamically generated by the reaction between hydrochloric acid (HCl) and ammonia (NH₃) vapors. The sensing mechanism and detection sensitivity of the chemical product is also discussed in the presentation.

© 2016 Japan Society of Applied Physics, Optical Society of America