Research Of Super Resolution Focusing Technology Of Metal/Dielectric Multilayers

In recent years, research about super resolution technology has gained more and moreattentions and huge development. Many novel metamaterials and superlens have beenproposed. Especially, metal/dielectric multilayers hold a very important station in thesuper resolution technology due to its unusual dispersion relation and the ability oftransmission of evanescent waves by coupling to surface plasmonics. In this thesis, weproposed a series of focusing and imaging structures with super resolution based on thespecial optical property of metal/dielectric multilayers and discussed the sub-diffractionbehaviors of the multilayers. The main work and conclusions in the thesis are shown asfollowing:1. Super Fourier focusing device with single slit based on metal/dielectricmultilayers. By analyzing the dispersion relation and sub-diffraction behaviors of themultilayers and discussing the focusing property of Fourier zone plates, a new superfocusing structure with single slit is proposed. The structure combines the focusingperformance of the zone plates and the ability of transmission of evanescent waves ofthe multilayers. The focusing effect of the device has been demonstrated by numericalsimulation and experiment results. Comparing with the traditional design, the devicecould achieve a resolution of32nm in theory, which is about one tenth of the workwavelength365nm, greatly surpassing the diffraction limit. The device has the potentialapplications in nano-scale lithography, microscope and optical storage.2. Super resolution lens with multiple slits based on metamaterials withhyperbolic dispersion relation and analysis of its off-axis focusing characteristic. Byutilizing the phase modulation of the Fourier zone plates and enhancement of theexcited efficiency of the surface plasmonics by MIM waveguide arrays, an improvedsuper focusing lens with multiple slits is proposed based on metamaterials withhyperbolic dispersion. Comparing with the traditional Fourier plates, resolution isimproved significantly with reduced side lobes levels. Then off-axis focusing characteristic of the lens is examined and analyzed using analytical method. Accordingto the analysis and numerical simulation results, which results in the image aberrationsis explained and the conditions to reduce aberrations and enlarge the focusing viewingregion are discussed. The work gives a useful support to the research about superresolution imaging and focusing technology with multiple object points and largeviewing region.3. Research about demagnification imaging device with hyperlens usingplasmonic reflection silver layer. By utilizing the magnifying and enhancing effect tothe evanescent waves of the plamonic reflection layer, a novel hyperlens structure isproposed, which could be used in subwavelength demagnification imaging andphotolithography. The hyperlens can achieve a half-pitch resolution down to15nm with30nm space by optimizing the geometry parameters while analyzing the influence of thelight polarization to the resolution based on a simple mathematical model.