【作者】 胡晓；

【导师】 夏宇兴； 詹黎；

【作者基本信息】 上海交通大学 ， 光学， 2008， 博士

【摘要】 亚波长结构金属薄膜中光的异常传输效应的发现为在金属薄膜中控制光子的运动提供了有力的工具,其机理和应用的研究是目前国际上研究工作的一个热点。本文对周期和准周期结构金属薄膜中异常传输效应的机理和应用进行了深入研究,具体内容如下:运用耦合波理论解释了亚波长周期性结构金属膜中异常传输效应的物理机理,理论清晰证明了异常传输现象的产生机制源于金属孔辅助下的入射光与表面波的瞬衰场的耦合,金属薄膜中的小孔对异常传输现象的产生提供了关键的耦合条件,而周期性结构为传输增强提供了位相匹配条件。耦合波理论不仅较为简单,且物理意义清晰。对准周期结构金属薄膜的异常传输现象进行了研究,详尽研究了Fibonacci小孔链的异常传输谱。由于Fibonacci结构中的多相位匹配机制,异常传输谱具有多重分形结构。计算了随Fibonacci序列长度而变化的标度因子,并用FDTD模拟证实了表面等离子模场的局域性。研究表明可以用异常传输谱的性质来预测表面等离子波的模场分布,这对于准周期结构金属薄膜在新型纳米表面等离子体器件的开发应用具有较大作用。本论文还探讨了具有亚波长结构的金属薄膜中异常传输现象的应用。根据周期结构金属薄膜异常传输现象的波长选择性,提出了一种新型的彩色滤波器的设计构想,并探讨了其优化设计方案。这种滤波器特别适用于OLED的彩色显示,它不仅具有结构紧凑的优点,还可以作为OLED的电极,同时其所具有的异常传输效应可以提高OLED的光能抽取率。用傅里叶分析方法研究了具有取样周期结构的金属薄膜的异常传输现象,并探索了其应用。分析了这种结构的多峰异常传输性质,以及结构参数对传输谱的影响。利用此性质可以研制结构紧凑的滤波器,在多波长光谱分析和多波长发光器件上可以有较大应用前景。基于这种结构,还设计开发了双波长滤波器,它具有同时增强荧光发射强度和提高信号光抽取率的作用,并适宜于小型化,适合在芯片上集成,以及大规模生产,特别适用于微全分析系统的双波长荧光测试。更多还原

【Abstract】 Since its discovery in 1998, the phenomenon of extraordinary optical transmission has arroused a worldwide enthusiasm to research on its physics mechanism and its application. This work emphasizes on the study of the mechanism of extraordinary optical transmission through periodic and quasiperiodic subwavelength hole array in metal films.Classical coupled-wave theory is used to analyze the coupling process between light and the surface plasmons wave on metal films with hole array. The analysis shows clearly the physical mechanism of extraordinary optical transmission is that the SPP plays the main roll in this process. The calculation demonstrates that, instead of energy flux directly passing through the holes, the electromagnetic modes could exchange energy by overlapping the evanescent fields under the assistance of hole array. The periodicity of the array provides the momentum-matching condition to present the transmission peaks. The theory exhibits a good agreement with the experimental results reported and is simple and clear.Extraordinary optical transmission on quasiperiodic-structured metal film is also studied. The feature of extraordinary optical transmission of Fibonacci chain of subwavelength holes on metal film was theoretically investigated. Owing to the multiple phase-matching mechanism in Fibonacci chain, the multifractal transmission property is found. The scaling effect on transmission spectrum with increasing Fibonacci sequence is obtained at the quarter-wavelength optical thickness. This behavior can be considered as the evidence for the localization of the surface plasmon mode on quasi-periodic structure, which was verified using FDTD simulation. Because of the possibility to predict the spatial distribution of localized plasmon modes through the transmission spectrum in quasi-periodic structure, this study has a significant impact for the design and fabrication of novel nano-plasmonic devices. Using metallic film perforated with sub-wavelength periodic structure, a novel concept color filter for multi-color OLED display is proposed. Based on the phase-matching condition for extraordinary optical transmission, three primary color emissions can be obtained by optimizing the structure’s periodicity. Discussion is presented to improve the purity of these filters. It is important that this type color filter simultaneously fineness the low emission efficiency problem for OLEDs with the aid of enhanced transmission of metal film.Optical transmission properties of sampled-period subwavelength metallic hole array have been studied using Fourier transform analysis. The multiwavelength enhanced transmission feature is found, which is due to multiple phase-matching in this structure. Through changing the sampling parameters, the interval between transmission peaks and the intensity distribution can be adjusted for special applications. It is important that a novel kind of multi-wavelength optical micro-filter has been proposed to exploit the application of periodic hole array structure. Based on this special structure, a novel optical filter is also developed for dual-wavelength fluorescence-spectrometry, structure parameters are analyzed to meet the requirement of dual-wavelength transmission in mTASs. With the features both to enhance the fluorescence generation and to enhance light transmission, in addition with the feasibility for miniaturization, integration on one chip and mass production, the proposed filters are promising for the realization of dual-wavelength fluorescence- spectrometry in micro-total- analysis-system.更多还原