Kırınım ağı tabanlı plazmonik kovuklar

Surface plasmon polaritons are dipole carrying electromagnetic excitations occur-ing at metal-dielectric interfaces. Metallic periodic structures exhibit modi¯edtransmission and re°ection spectra owing to the interaction of propagating SPPswith the periodicity. These periodic surfaces are used to demonstrate localiza-tion of propagating SPPs. Thin metallic ¯lms surrounded by Bragg re°ectors,selective loading of biharmonic metallic surfaces and Moire patterns are used todemonstrate plasmonic cavity formation. The quality factor, Q, a characteristicvalue that indicates rate of energy loss relative to the stored energy in the cavityis a crucial parameter for classifying these cavities. It was proposed that theQ factor should strongly depend on the surface geometry. However, there wasnot a sytematic study on the Q factor of these cavity structures. In this work,we report on a comparative study of grating based plasmonic band gap cavities.Numerically, we calculate the quality factors of the cavities based on three typesof grating surfaces; uniform, biharmonic and Moirµe surfaces. Experimentally,we demonstrate the existence of plasmonic cavities based on uniform gratings.E®ective index perturbation and cavity geometries are obtained by additionaldielectric loading. Furthermore, we fabricate 2D plasmonic structures, observeplasmonic band gaps in the symetry axis and propose cavity geometries for thisstructure.