Preparation, characterization and application aspects of functionalized photonic crystal fibers

光纤是现代光电子和通信系统的支柱。因此，他们对光学特性的控制工程是当代研究和技术的主要目标。一种新型光纤被称为光子晶体光纤（PCF）。PCF是一种具有或多或少规则排列的轴向空气孔的光纤，其核心可以由空气（光子带隙光纤）或宿主材料（多孔光纤）制成。这些纤维可能表现出各种具有应用吸引力的特性。该项目的目的是设计和可复制地制造两种类型的PCFs，使其具有最小的损耗，可控的模态形状和光谱依赖性，色散和偏振特性。为此，将详细研究光学性质对PCF几何形状和材料组成的依赖关系。因此，不同掺杂材料和不同几何结构的PCFs的制造技术将被研究。将理论建模和实验结果进行比较，并对设计进行相应的优化。可能的应用，如激发大面积模式，非径向对称和偏振依赖的模式分布，以及频谱宽带单模传输和结构照明的模式分布将被研究。

Optical fibers are a backbone of modern optoelectronics and telecommunication systems. Thus, their controlled engineering with respect to the optical properties is a primary goal of contemporary research and technology. A novel type of fibers is the so-called photonic crystal fiber (PCF). PCF is a fiber with more or less regularly arranged axial air holes where the very core can be made either from air (photonic band gap fiber) or from host material (holey fiber). These fibers may exhibit various peculiarities attractive for applications. The aim of the project is to design and reproducibly fabricate both types of PCFs with minimized losses, controllable modal shape and spectral dependence, dispersion and polarization properties. To this end the dependence of the optical properties on both the PCF geometry and the material composition will be studied in detail. Thus, fabrication technologies for PCFs with differently doped materials and for different geometrical structures will be investigated. Theoretical modeling and experimentally achieved results will be compared and the design will be correspondingly optimized. Possible applications as the excitation of large area modes, nonradial symmetric and polarization dependent mode destributions as well as spectrally broadband single mode transmission and mode distributions for structured illumination will be investigated.