周期性微结构的制备及其修饰光纤的技术研究

【作者】 倪海彬；

【导师】 王鸣；

【作者基本信息】 南京师范大学 ， 物理电子学， 2014， 博士

【摘要】 由介质构成的三维周期性结构具有光子带隙特性,金属／介质构成的二维周期性结构能够被激发形成表面等离激元模式,这些特性可以用于生物、化学传感。本文提出在光纤的端面用自组装方法制备蛋白石(Opal)、反Opal和复合三维光子晶体,形成三维光子晶体传感应用的平台,进一步研究有潜力形成微结构光纤传感器。将这一设计推广到二维周期性结构,用自组装法在光纤端面和侧表面制备单层微球阵列和单层复合微球阵列,通过对微球阵列的形貌修改和沉积金属薄层,在光纤端面和侧表面能够形成多种形貌的亚微米尺度的二维周期性金属/介质结构,这种方法简便,可靠,成本低,可规模化生产。本文还研究在毛细管内壁制备高质量的空心圆柱形反Opal光子晶体,为制备反Opal光子晶体光波导提供一种可行方案。研究用溶胶凝胶协同自组装法制备单层复合微球有序阵列,并采用反应离子刻蚀等技术改变微球阵列的形貌,得到多种形貌的二维周期性结构；研究了结构参数和Ag膜厚度对二维周期性结构反射光谱的影响,实验测试了几种二维周期性结构的反射光谱与入射光角度和偏振之间的关系；研究岛型二维周期性介质/金属复合结构用于液体折射率测量和用作SERS基底的特性。研究用垂直沉积法和溶胶凝胶协同自组装法在光纤端面制备Opal、反Opal光子晶体和复合光子晶体的实验装置和参数,设计采用了两种光纤结构：光纤束和光纤-毛细管结构,实现光纤端面高质量多种周期尺寸的三维光子晶体沉积；表征了实验样品的微观形貌,测试了样品的反射光谱,分析光纤端面光子晶体的厚度对反射光谱的影响,测试分析光纤束中光子晶体薄膜的反射光谱的分布特性；实验测试Opal、反Opal、复合光子晶体的相对湿度传感特性及液体折射率传感特性。研究在光纤端面制备单层PS微球和单层复合微球阵列的试验参数,以PS微球作为掩膜板在光纤端面形成二维周期性金属Ag的图案；对单层复合微球阵列进行形貌刻蚀修改,并沉积金属Ag,在单模光纤端面得到多种形貌的金属／介质周期性阵列。研究在毛细管外壁、内壁制备高质量的反Opal光子晶体的试验参数,测试了制备的空心圆柱形反Opal光子晶体的透射光谱；在毛细管内制备实心反Opal光子晶体圆柱,分析其内部结构,测试其端面和侧表面的反射光谱。研究在光纤侧表面用溶胶凝胶法制备单层复合微球阵列的实验参数。更多还原

【Abstract】 Three dimensional periodical structures composed of dielectric materials possess a photonic band gap while two dimensional periodic metal/dielectric materials can support the surface plasmon polariton modes, both of the two kinds of periodic structures with unique optical properties can be the good candidate for biological and chemical sensors with miniature size. In this thesis, we proposed to assemble opal, inverse opal, and composite photonic crystals on optical fiber end facets to form a platform to realize practical sensing applications and some other. The prposed scheme may potentially form a serial of microstructure optical fiber sensors with further development. Due to the low cost but high productivity technique used in these structure fabrication, the proposed photonic crystals based optical fibers are adaptable for industry manufacture. Furthermore, two dimensional periodic metal/dielectric structures with variable morphologies and structure parameters which are formed by modification of monolayer close packed spheres can also be fabricated on end facets of optical fibers as well as their side surfaces. In addition, a method to produce high quality hollow cylindrical inverse opal films is proposed and demonstrated, which affords a possible option to fabricate inverse opal waveguides.Sol-Gel co-assembly parameters as well as morphology modification conditions of the monolayer composite Polystyrene (PS) microsphere arrays are investigated, and several two dimensional periodic arrays with different morphologies are obtained in large area with few defects. Followed by sputtering a layer of Ag film on these structures, optical reflection spectra of the two dimensional metal/dielectric structures which depend both on the Ag film thickness and the structure parameters are measured and analyzed. Moreover, dependence of reflection spectra of these structures on varied incident light angles and polarization are also investigated. Performance of island like two dimensional metal/dielectric structures which used as liquid refractive index sensor and surface enhanced Raman scattering (SERS) substrate is analyzed.Two kinds of fiber structures, optical fiber bundles and fiber-capillary structures, are designed to deposite high quality opal, inverse opal, and composite photonic crystals by self-assembly method. A home-made setup and the corresponding experiment conditions are developed to perform the experiments. As a result, after scanning electron microscope examination and optical reflection spectra testing, three kinds of photonic crystals in high quality with different length of periodicity can be formed on end facets of both optical fiber bundles and fiber-capillary structures. By analyzing the experimental data, features of reflection spectra on thickness of photonic crystal films as well as the distribution of reflection peak wavelength of fibers in a bundle are plotted, which agree well with simulation results. Moreover, relative humidity and liquid refractive index sensing performance of the three kinds photonic crystal films were demonstrated.Monolayer of close packed PS microsphere arrays and composite PS microspheres films are deposited on optical fiber end facets and their side surfaces by vertical assembly and sol-gel co-assembly method with modified experimntal parameters. A layer of two dimensional periodic Ag film is deposited on fiber end facets by using monolayer PS microsphere arrays as deposition mask. Similarly, according to the above mentioned fabrication technique, two dimensional periodic metal/dielectric structures with different morphologies are also produced on optical fiber end facets and their side surfaces.High quality hollow cylindrical inverse opal films produced on outer and inner surface of a capillary by sol-gel co-assembly method is demonstrated. Optical transmission spectra in different positions along the cylindrical axial directions were measured. Also, an inverse opal column embedded in a capillary was fabricated, and its inner structure as well as the optical reflection spectra perpendicular to its top and side surface was explored.更多还原