THz Surface Waves, Waveguide THz-TDS and the 2D-TEM Plane

Oklahoma State University, Stillwater OK

Investigators

Abstract

This experimental research program will explore fundamental optical physics and applications using far-infrared terahertz (THz) radiation. The PI has previously extended the concept and utility of parallel-plate waveguides to that of a much larger two-dimensional plane. Within this plane two-dimensional quasi-optical elements have demonstrated THz guiding and diffraction. This project will investigate optical physics with recently designed two-dimensional quasi-optical components with negative index of refraction. Researchers will measure the refractive properties and assess the utility of these extremely dispersive components. In addition, the program will experimentally measure and theoretically study the propagation of THz surface electromagnetic waves (plasmons) on planar subwavelength arrays of holes in thin metal films. The experiments are designed to resolve a discrepancy with the theoretically predicted very large transverse extent of the THz surface plasmons and previously observed transmission through hole arrays. The program will transform the previously developed technique of waveguide THz Time-Domain Spectroscopy into a new spectral analysis technique with high sensitivity and frequency resolution for sensing and measuring the properties of thin layers of material. This sensing technology is of great technological importance and the techniques are of major interests to many fields including organic chemistry and molecular biology. The researchers will assess the comparative strengths of sensing techniques using surface plasmons or parallel-plate waveguides in the THz spectral range. The versatility and usefulness of the two-dimensional waveguide plane for reduced scale instrumentation will be demonstrated. This project will also provide multidisciplinary research training for students and postdoctoral researchers in optical science, terahertz physics, and molecular sensing.