Tailoring Artificial Dielectric Materials at Terahertz Frequencies

The Submillimeter Technology Laboratory(STL) at the University of Massachusetts Lowell has developed a methodology of tailoring the complex refractive index for artificial dielectrics at terahertz frequencies. A wide range of precisely controlled optical properties have been achieved for materials such as vinyl acetate, silicone, polyethylene and epoxy resin when combined with powdered loading agents such as boron nitride, silicon, graphite, iron oxide and stainless steel flake. Using this technology, STL has successfully fabricated both narrow-band and wide-band anechoic structures. The method of characterizing materials for the purpose of tailoring their dielectric properties at terahertz frequencies is presented along with several demonstrated applications. 2. Introduction Because of the increase in the number of optical and quasi-optical measurement systems operating at terahertz frequencies, new materials providing alternative solutions to the design of system components are required. In response to this, STL’s recent activities include an aggressive program to evaluate a wide range of materials for terahertz frequency applications(1-3). Using inhouse expertise in the technique of tailoring artificial dielectrics and the polarimetric characterization of materials, a variety of composite structures have been created as far-infrared radiation absorbing material (FIRAM)(4,5). metal substrate dielectric layer { { incident radiation