Study On Metal-dielectric Subwavelength Waveguide Structure

Along with the widely using of technology of optical switching ,the fiber opticalcommunication technology develops fast and all-optical networks will be more intelligent flexibleand configurable in the future .The situation of optical communication network adopts all-opticaltechnology in the middle transmission network ,but the terminals are still using electrical switchingtechnology .Optical signal must change into electrical signal when Optical signal is transmitted .Itseriously affected the signal transmission rate ,and increase the complexity and cost ofequipment .Finally, the quality of the communication is declined .Optical networks difficult toachieve all-optical ,One of the most important reason is because the current photonic devicesaffected by the diffraction limit ,which limits the miniaturization of photonic devices.It is difficult to integrate more devices into the volume of a certain size ,namely improve theintegration of photonic devices ,which hinders the development of optical communicationtechnology .Researchers have proposed various techniques used to reduce the size of photoniccircuits .Of Which the surface plasmon (SPPs) technology is one of the most promising technology.SPPs is essentially interaction of free electrons and electromagnetic field propagation along themetal surface electron density wave, thus breaking the barrier set in conventional opticalwaveguides by the diffraction limit.Based on the analysis of metal-dielectric subwavelength structure of the waveguide surfaceplasmon (SPPs) in the optical excitation process and optical phenomena (such as: couplingresonance, wavelength division, etc.), this thesis brings up their interpretation of physical processesand mechanisms, and establishes the relevant theories. Through the material selection and design ofmicro-morphology, micro-structural parameters of the selection and adjustment of metal-dielectricsubwavelength waveguide structure, it studies on the effective excitation of SPPs mode and theoptical properties of coupled light waves. On the above basis we actively research metal - mediumsubwavelength structure of optical waveguide coupling phenomena and transmission enhancephenomenon, design a kind of metal-medium subwavelength structure waveguides, research fourdifferent microstructures of cylinder,triangular,cube and prism stimulating SPPs, observe thecoupling enhancement and the effect of dividing wave, found triangle structure couple wave for thebest results, runs up to 70%-80%. According to the above conclusions design of multi-channel divide wave implement, choice silver triangular microstructure, set seven channels. By adjusting themicrostructure Angle this divide wave is achieved to optical wavelengths from 1.30μm to1.60μm , and the simulation result of wave 50nm interval of light waves have good results, itprovide for a new idea to the new WDM and passive optical device fabrication.Finally according to the conclusions of this thesis, it brings up the possibilities and advantagesof using anisotropic dielectric materials to make metal - dielectric subwavelength waveguidestructure.