| Nanophonotics, based on surface plasmon polaritons (SPPs), is well developing to satisfy the needs of high-density and high-speed information technology. Manipulating and controlling light in subwavelength scale using SPPs is a hot topic all over the world. Surface plasmon polaritons (SPPs) are surface electromagnetic waves which propagate along the interface of two media, where the dielectric constants have opposite signs. The merits of SPPs, like subwavelength localization and near field enhancement, play an important role in nano-optics. The SPPs surpass the diffraction limit and are localized on the order of, or less than, several tens of nanometers inside the optimized metal-dielectric waveguide. As a result, the high integrated nano-photonic chips hold great potential for the realization of nano-photonic integration. Furthermore, SPPs are prospective routes to advancing various fields with many applications such as optical data storage, optical sensors and super-resolution imaging. The research on SPPs has already been an emerging discipline, Plasmonics, which is one of the main branches of nanophotonics.The thesis is mainly focused on the application of SPPs in functional waveguides, nano-photolithography masks, and nano optical antennas using numerical calculation (Finite-difference time domain(FDTD) method and discrete dipole approximation(DDA) method), mainly discussing the questions as follows:1. A novel chamber-channel system is proposed to achieve the bending of light at a90c angle with relatively high transmission efficiencies by DDA method. An ultrathin film is introduced into the chamber to couple more light into the system, which makes the chamber as a light absorber, while the channel serves as an output pathway to guide the light through the system. We show that the light propagation is significantly affected by the output position of the channels. The relationship between the positions as well as number of the outputs and the transmission conditions of light are disscussed. This work holds great potential for controlling light in nanoscale photonic devices.2. A two-layer silver film system is proposed to accomplish light localization and direction selective propagation by DDA method. The waveguide with an angled hole array embedded in a one layer silver film was proposed to achieve light propagation with directional selectivity in narrow space as small as10run. When in resonance, the system could manipulate the direction of light propagation efficiently. The structure was changed so that the angled holes were replaced by vertical holes and the localization between the two layers is discussed. The results showed that the light could propagate inside the interspace of the film with a cross section of10x20nm2. These studies provided a new way to control the direction of light propagation, as well as light compression.3. Indentations etched on the output surface of a metallic mask are proposed to produce fine lithographic patterns with a resolution of500nm using FDTD method. Such a designed mask is capable of enhancing near field lithography resolution more than three times compared with the structure without indentations. The simulation results show that the interference disturbance between the adjacent lithographic channels can be eliminated efficiently by employing the indentations. As a straightforward consequence, the channel-to-channel interspaces can be shortened significantly, maintaining a uniform field distribution and high contrast. The improved mask is promising in large-area, high resolution photolithography.4. Optical properties of bowtie antennas are investigated using FDTD method. The optical response in the antenna feed gap is simulated as functions of its geometry parameters (flare angle, arm length, apex width, thickness, gap dimension, as well as the index of substrate), which provide a clear guideline to exploit such antenna structures in practice. |
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