Characterization of Material Properties at Terahertz Frequencies

Abstract

Abstract : In the realm of materials science, terahertz frequency measurement systems provide significant utility in the characterization of material properties. With support primarily from the U.S. Army National Ground Intelligence Center (NGIC), Submillimeter Technology Laboratory (STL) researchers have been advancing the field of terahertz technology to the application of modeling millimeter-wave and microwave radar for more than a decade. Research in modeling radar requires design of a wide range of measurements systems using current submillimeter-wave source/detector technology, establishment of precise calibration standards, production of high fidelity scale replicas of complex metallic structures, and scaling of millimeter-wave dielectric properties of composites at submillimeter-wave frequencies. This paper explores four measurement techniques typically employed by STL to perform the characterization of materials: (1) laser-based submillimeter-wave ellipsometry; (2) high-precision reflectometry; (3) laser-based Brewster' s angle measurements; and, (4) FIR Fourier transform spectroscopy (FTS).