Study Of Hybrid Plasmonic Micorcavity Resonance And Induced-transparency

Surface plasmon is a transverse magnetic(TM) optical suface wave that propagatesalone a metal-dielectric interface. Due to the ability of propagating in subwavelengthscale, surface plasmon waveguides have attract a lot of attention. Among the numeroussurface plasmon waveguides, hybrid plasmon waveguides, incorporating metal, low andhigh index materials, are considered to have unique advantages in the trade ofconfinement and propagation distance. Based on this reason, to achive high quality factors,hybrid plasmon structures were utilized to make up a ring microcavity in this thesis. Theresonance characteristics of the microcavity were studied, and then by adding metalnanorods around the microcavity, the influence of the nanorods was disscuessed. Theelectromagnetically induced-transparency phenomenon was simulated in the single modewaveguide using nanorod micocavity. The major work was summarized as follows:By changing the relative position between the dielectric nanoring and metal surface,four different kinds of dielectric nanoring-dielectric-metal hybrid plasmonic ring cavitieswere designed. The electric field distribution of the microcavities with differnet structureand mode order was calculated. The quality factor of the microcavities was studied withthe changes of the radius of the microcavities, the length and width of the nanoring, therefractice index of dielectrics and the gap width between the metal surface and nanoring.We analysed the influence of the geometric parameter and summarized the variation ofthe quality factor.Then, we discussed the resonance characteristics of the micocavities after adding themetal nanorods including the quality factor in different number, radius, height, distanceof the nanorods. The relationship among the quality factor, mode order and the numberof the nanorods was investigated and the requirements of relatively high quality factorwas also given.Using the nanorod microcavity, we theoretically demonstrated the EIT-like effect ina single-mode waveguide with nanorod cavities aside, and then discussed the resonancecharacteristics and transparency window as the distance between the nanorods changed.We also designed a special device consisted of two symmetric placed nanorodmicrocavities. The EIT phenomenon can be easily achived when putting a single mode waveguide in the middle. The group index was calculated as the EIT phenomenonoccurred, and slow-light effect was realized in near-infrared frequencies. The result wascompared with the situation of single nanorod cavity.