Surface plasmon polaritons excited over sub-wavelength aluminum structures by terahertz radiation

摘要

A two-layered construction composed of micro-nano-structures is fabricated to investigate the key properties of surface plasmon polaritons (SPPs) in the range of terahertz wave. The construction is mainly two layered micro-nano-structures (MNSs), and the utilized substrates are silicon materials currently. One silicon substrate is covered by a layer of indium tin oxide (ITO). Another silicon substrate is sputtered by a thin aluminum film, which is further patterned to shape functioned sub-wavelength aluminum structures (SWASs). Both aluminum film and ITO film are coupled to form a micro-cavity using micro-spheres spacers. The typical terahertz (THz) transmission of the construction is measured. The experimental results demonstrate that some extraordinary transmission peaks called the extraordinary optical transmission (EOT) appear in THz transmittance spectrum. The analysis results indicate that THz radiation excites effectively SPPs over the SWASs.