A Research On Optical Properties Of Metallic Nanoparticles Structure And Its Application In Optical Storage

In traditional optical disk system, the recording density of optical disk is increasedthrough decreasing the laser wavelength and increasing the numerical aperture of objectlens. It has been found that metallic nanostructures demonstrate the unique phenomenonof extraordinary optical transmission(EOT), which is originated from the localized surfaceplasmon resonances(LSPRs) of metallic nanostructures. Due to the surface plasmonresonances, some metallic nanostructures will present a special nonlinear optical propertyin the spectrum, such as electromagnetic induced transparency(EIT) and Fano resonance.The nanostructures can be designed as recording marks by using the unique characteristics.It’s better for the acquisition of the recording marks’ signal through the optical spectrumchanges, and realizing the surface plasma optical storage.The main results of this paper are as followed.(1) The application of metallic nanostructures in surface plasmon optical storagetechnology based on the principle of surface plasmon is studied. We also primitivelyintroduce the write and read out method employed in our plasmonic data storage system.(2) A hybrid nanostructure composed of metallic nanotriangle and nanorod(s) isproposed as a recording mark in optical storage. A three dimensional finite difference timedomain(FDTD) method is employed to simulate the optical properties of the proposednanotriangle and nanorod(s) hybrid nanostructures. Electromagnetically inducedtransparency(EIT) is observed in the hybrid nanostructures. The underlying physicalmechanism of EIT is investigated based on the electric field and charge distributions.When the gap between the nanotriangle and the nanorod, or the number of nanorods, orthe length of nanorods is changed, the hybrid nanostructure is feasible to be used as arecording mark due to the spectral characteristics changes regularly.(3) A oligomer nanostructure consisting of five metallic nanorings is designed todemonstrate the applications of nanoparticles in plasmonic optical data storage. Fanoresonance appears to change correspondingly and shows a certain regularity when wechange the recording mark’s parameters such as size, shape, symmetry, et al. Its Fano resonance’s physical mechanism is analyzed according to the extinction spectra and itselectric field and charge distribution. The nonlinear characteristics originally appear in thefield of quantum influenced by the change of the geometry quite sensitively, which makesit have a very broad application prospect in nano optical information storage technology.