Terahertz Spectroscopy and Imaging With Flexible Tube-Lattice Fiber Probe

A flexible tube-lattice fiber is introduced into a terahertz time-domain spectroscopy system as a probe in an endoscope geometry and used to guide radiation to and from a sample. This allows hyperspectral imaging to be performed by scanning the endface of the probe, rather than the sample or components of the terahertz system itself. Hyperspectral imaging is demonstrated through the identification of various substances in the image and visualized through the implementation of a false-color system. The resolution of such an imaging system is discussed and quantified, finding excellent agreement with the experimental measurements.