Subwavelength plastic wire terahertz time-domain spectroscopy

Abstract

This work demonstrates the feasibility of a terahertz time-domain spectrometer based on a subwavelength-diameter plastic wire (SPW) for sensing applications. The dispersion property of the SPW is experimentally and theoretically studied. The SPW exhibits a low and controllable waveguide dispersion, which can be engineered by changing the core diameter, the core index, and the cladding index of the wire. Two white powders, tryptophan and polyethylene, deposited on the bottom of the wire can be successfully distinguished based on the waveguide dispersion of SPW. The SPW would be a promising candidate for combination with biochips for sensing minute molecules.