The Characteristic Research Of Surface Plasmon Polariton Based Optical Fiber

The SPPs has some attractive features such as tighter spatial confinement and higher local field intensity. It is able to overcome the conventional diffraction limitation, which leads to various potential optical applications in the case of optical storage, switching and filter.Based on the SPPs transmission theory in dielectric, this thesis discusses the variation in the structure with different parameters. It also studies the application of the SPPs in optical filter, switching and sensor. The main contributions are as follows:1. The simulation conditions and theories of the SPPs transmitted in waveguides are studied. Meanwhile, the characteristic of the structure that has a symmetric double ring resonator is analyzed. The results indicate that several parameters such as the width of the ring w, the width of the waveguide d and the radius of the ring r have significant influence on the transmission. In addition, the gaps w only have effects on the transmission value. Based on the simulation results, this kind of structure can act as an optical pass-band filter. By changing the position of rings, some structures which can act as an optical stop-band filter.2. The asymmetric waveguide was analyzed numerically by changing the radius of the ring and coupling space between the ring and the waveguide. The results show that the asymmetric structure has smaller rising bandwidth than that of the symmetric one, which means a small shift of the spectrum leading to the transmission value from the top to valley. According to this, BL009mixture was selected as the infiltrated liquid crystal material in order to fill the rings. As the voltage between the inside and outside of the ring changes, the refractive index of BL009changes correspondingly. In addition, the spectrum of the transmission curve shifts, making the structure a switch that works near a certain wavelength. This research provides insights to the potential application of micro optical switch.3. A metal film was disposed on the core of optical fiber, and SPPs was excited between the core and the metal film. The relation between the thickness of the metal film and the refractive index of the core and medium was calculated and simulated. The results show that for a certain thickness of the metal, the fiber is susceptible to the changes of the medium refractive index in a certain section. This characteristic can be used as a sensor to detect a medium.In conclusion, this thesis is based on SPPs in the waveguide, and studies the structure and function of waveguides. Results presenting in this thesis increases our understanding of the micro optical devices.