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Terahertz Surface Plasmon Polaritons On Metal Surfaces Corrugated By Shallowly Periodic Grooves

Posted on:2013-02-09Degree:MasterType:Thesis
Country:ChinaCandidate:Y Y ZhangFull Text:PDF
GTID:2218330374962423Subject:Computer application technology
Abstract/Summary:PDF Full Text Request
The routing of terahertz waves by an array of shallowly periodic grooves on metal surfaces is investigated theoretically. The spoof surface plasmon polaritons (SSPPs) supported by a textured metal surface fabricated with one-dimensionally periodic V-shaped grooves are studied firstly. The dispersion relationships, absorption loss, and field confinement as the geometric parameters of the v-shaped groove change, which demonstrates that the frequencies of the surface plasmon plaritons were determined by the geometric parameters, moreover, are analyzed, and the research shows that the groove depth has a great effect on the properties of the SPPs including the loss, and on the contrast, the groove width has a small effect on the properties of the spoof SPPs. However the depth of the grooves is sometimes be limited due to the thickness of the metal surface. It is interesting to study the properties of spoof SPPs on metal surfaces structured with shallow grooves, for the development of THz plasmonic devices. Then the dependence of the properties of spoof SPPs on the transverse geometries of the shallow grooves is studied. It is shown that asymptotic frequency is much sensitive to the bottom width of the grooves. A larger bottom width of the grooves corresponds to a lower asymptotic frequency, and the type of the trapeziform grooves has the best field confinement than the types of the V-shaped grooves and the vertical grooves. Then studies are carried out to know clearly the properties of the spoof SPPs of the trapeziform grooves which has the best field confinement. Two types of grooves (horn typed grooves and vertical grooves) with the same transverse areas are also studied for comparison. The influences of the the absorption of metal at THz frequencies on the performance of spoof SPPs with the trapeziform grooves are also examined. The light guiding properties of the surface with such structure are studied. At last,surface plasmon polaritons (SPPs) propagating along a metal surface corrugated with an array of shallow grooves filled with dielectric (air, PE and Si) are studied analytically. It is shown that the asymptotic frequency of SPPs can be greatly decreased by stuffing the grooves with dielectric, and thus the fields exhibit much better confinement. In the THz frequency range, the influence of the absorption in real metal on the performance of spoof SPPs is also examined. The numerical calculations show that long propagation length and subwavelength field confinement are simultaneously available for spoof SPPs on the real surface corrugated with grooves stuffed by the dielectrics. The good guiding ability of the structured surface at THz frequencies is further verified by numerical simulations of wave transmission.
Keywords/Search Tags:Surface plasmon polaritons, terahertz radiation, waveguide, subwavelength field confinement
PDF Full Text Request
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