The Study Of Optical Transmission And Perfect Optical Absorption Effect In Novel Metallodielectric Hybrid Plasmonic Microstructures

Benefit from the developed nano-science and technology, various metallic nanostructures have been designed and fabricated out. These metallic nanostructures possess unique and various functional properties, which have presented great potential for applications in the research fields of surface enhanced Raman scattering (SERS), integrated circuits (IC), biosensors, data storage and optical antennas. Meanwhile, it has merged into a new rapidly growing discipline, named as plasmonics, which covers the research area of physics, chemistry, material science, information science, biology, and their inter-disciplines.In this thesis, we will detailedly show the fabrication of the composite metallodielectric microstructures. The enhanced optical transmission (EOT) and perfect optical absorption phenomena in these metallodielectric microstructures have been investigated both in experimental and calculation. We have proposed a novel perfect electromagnetic waves absorption plasmonic system with polarization-independent, broad bandwidth and wide angle. The proposed system is with several merits, including the simple technique requirement, low cost, large area and high reproducibility. In the following study, we find out that the bandwidth of the plasmonic absorber could even significantly broadened by the mixture of different size unit cells. Overall, our results could supply a new alternative approach of the light perfect absorber, and also suggest a novel investigation object and a high efficiency fabrication method for the worldwide peer researchers. The thesis is mainly composed of three sections that are arranged as following:1、By utilizing the two dimensional (2D) colloidal crystal fabricated by the self-assembling of polystyrene microsphere as the template, we fabricate the metallodielectric hetero-colloidal crystal by utilizing the vacuum ion-beam sputtering deposition method. The detailed optical transmission properties of this kind plasmonic microstructure have been investigated in this thesis. It is found out that the resonant optical transmission properties could be highly tuned by introducing a dielectric layer between the up gold cover layer and the colloidal crystal. This optical transmission phenomenon is similar to the EOT observed in the metallic fishnet structure. Based on the finite element method, we do numerical study on this kind plasmonic crystal. By the study of the modes, we propose the EOT is based on the contribution from the coupling between the localized sphere-like surface plasmon (SP) mode and the confined optical guided mode (GM) in the microspheres. Based on this kind metallodielectric hetero-colloidal crystal microstructure, we do study on the dielectric environment sensitivity and find out a better sensitivity factor of the metallodielectric hetero-colloidal crystal with a suitable thickness buffer layer than that without buffer dielectric layer.2、We obtain novel plasmonic microstructures by self-assembling a monolayer colloidal crystal on an optically opaque metal film followed by depositing a thin metallic half-shell on the top of the colloidal particles. By measured the reflection and transmission, we show the detailed light absorption response of this novel microstructure and achieve a dual broadband light perfect absorption for the first time in this kind system. This novel dual broadband light absorber has several merits including the polarization-independent, wide angle and broad bandwidth. In addition, it is found out that the proposed system here is with several practical advantages, such as the large area fabrication and production, very low cost, lower technique requirement and high reproducibility. By utilizing the finite element method, we do numerical study on the optical properties of this kind light absorber. The calculated light absorption spectrum with dual broad bandwidth spectrum shows good agreement to the experimental results. In particular, at the longer wavelength regime, the calculated results show a broad bandwidth high absorption band. By the study of the corresponding electric field intensity distribution on the central wavelength of the absorption band, we find out that the main electric field intensity is confined on the up metallic thin film. This kind pattern is very similar to that of the localized sphere-like SP mode which is a broad bandwidth plasmonic resonant mode. At the short wavelength regime, the calculated spectrum shows a broad absorption spectrum lineshape. The corresponding electric field distributions suggest that the high absorption would be the result of the coupling between the localized SP mode near the metal film and the optical resonant modes of the dielectric microsphere array. Based on the calculation and theoretical analysis, we also find out that the dual broadband light absorption properties could be modified by tune the geometry parameters, including the microsphere size, the dielectric index and the thickness of the metal film. Thus, the proposed structure is with spectral scalable and we can present broad bandwidth perfect light absorption from visible to infrared frequency regime.3、In this thesis, we further propose and experimentally verify a disorder ultra-broadband perfect light absorption effect. By using two different size colloidal microspheres mixing together, we do study on light absorption behavior of the disorder plasmonic system. We obtain the novel disorder plasmonic microstructures by self-assembling a monolayer colloidal crystal with some certain disorder on an optically opaque metal film followed by depositing a thin metal layer on the top of the colloidal particles. It is found out that this kind disorder microstructure could produce broader bandwidth of light perfect absorption than the order system formed by the single colloidal microsphere. We do further investigations on the modification of the light absorption properties by tuning the colloidal concentration ratios of the different microspheres and the sizes of the colloids. The obtained investigation results would show great contributions on the further study on the research and realization of the full visible light perfect absorption plasmonic microstructures.