Development of Chiral Negative Refractive Index Metamaterials for the Terahertz Frequency Regime

A novel negative refractive index (NRI) chiral meta-material (MTM), based on the Y structure, has been designed and tested in the microwave and terahertz frequencies. In addition to providing magnetoelectric coupling, this MTM has a negative index of refraction passband that can be tuned in both the frequency of operation and bandwidth with lower losses compared to other known chiral structures. Group theory was used to analyze the magnetoelectric coupling of the Y-shaped structure and circuit analysis was used to aid in the design of the NRI material and full-wave finite difference time domain (FDTD) simulations were conducted to determine the transmission characteristics of the material. Wedge-and prism-shaped models comprised of the designed structures were simulated to validate the NRI behavior and were then compared to experimental results in the microwave regime. Furthermore, the Y-shaped design was fabricated in the THz regime and the co-and cross-polarized transmission coefficients were determined from experiments and were compared to numerical results.