Enormous pressures have been puts on current optical storage technologies as the rapid development of information technologies. Recently, it has been found that the surface plasmon–polaritons'modes (SPPMs) in metallic nanostructures may lead to the high localization of guided light beams with nanometer size and only limited by several factors such as atomic structure, dissipation, and light dispersion, and thus far beyond the common diffraction limit of electromagnetic waves in dielectric media. This discovery provides a way to produce nanoscale light signal and thus makes a significant breakthrough in optical storage technologies. In this paper, our work focuses on the modeling and simulation of particular kinds of patterned metal-based nanostructure fabricated over silicon dioxide (SiO2) wafer. The nanostructures designed are expected to concentrate, deliver incident light energy into nanoscale regions and generate nanoscale light signal. In our research, the duty cycle of patterned nanostructures is taken as a key parameter, and then the factors including the patterned nanostructures, the frequency of the incident electromagnetic wave, the size of patterned nanostructure and the distance arrangement between adjacent single patterns, are taken as variables. The common CST microwave studio is used to simulate beam transportation and transformation behaviors. By comparing electric-field intensity distribution in nano-areas and the reflectance of the nanostructure array, the nano-light-emission effects are analyzed.
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.
Current researches show that the surface plasmon-polariton modes (SPPMs) in metallic nanostructures can lead to a powerful localization of guided light signals, which is generally as small as a few nanometers and thus far beyond the diffraction limit of electromagnetic waves in dielectric media. In this paper, our attention is paid to the modeling and simulation of particular kinds of patterned metal-based nanostructure fabricated over several common wafers such as typical silicon dioxide. The nanostructures are designed for concentrating and delivering incident light energy into nanoscale regions. In our research, the factors, for instance, optical materials, patterned nano-structures, the distance arrangement between adjacent single nanopattern, and the frequency of incident electromagnetic wave, are taken as variables, and further the CST microwave studio is used to simulate optical behaviors of the devices developed by us. By comparing the transmittance and electric field intensity distribution in small area, the nano-light-emission effects are analyzed, and the conditions for obtaining near-field nanospots have been chosen.
In order to investigate the key properties of surface plasmon polaritons (SPPs), a new kind of device based on sub-wavelength aluminum structures (SWASs) have been designed and fabricated with respect to incident radiation in terahertz (THz) range. The device is composed of two layered micro-nano-structures and the utilized substrates are silicon materials in current stage. One silicon substrate is sputtered directly by a thin aluminum film, which is further patterned to shape functioned micro-nano-structures. The THz transmission performances of the devices have been measured according to common optical approaches. The experimental results show that some extraordinary transmission peaks are clearly presented in terahertz transmittance spectrum, which is inconsistent with the classical aperture theory of Bethe. The effects of the developed SPPs are discussed carefully according to the discovered phenomena about the extraordinary optical transmission (EOT).