Preparation, characterization and application aspects of functionalized photonic crystal fibers

光纤是现代光电子和电信系统的支柱。因此，它们在光学性质方面的受控工程是当代研究和技术的主要目标。一种新型的光纤是所谓的光子晶体光纤（PCF）。PCF是一种具有或多或少规则排列的轴向气孔的光纤，其中核心可以由空气（光子带隙光纤）或基质材料（多孔光纤）制成。这些纤维可以表现出各种对应用有吸引力的特性。该项目的目的是设计和可重复地制造这两种类型的光子晶体光纤，具有最小的损耗，可控的模式形状和光谱依赖性，色散和偏振特性。为此，将详细研究PCF几何形状和材料成分上的光学性质的依赖性。因此，将研究具有不同掺杂材料和不同几何结构的光子晶体光纤的制造技术。将比较理论建模和实验结果，并相应地优化设计。可能的应用，如大面积模式的激发，非径向对称和偏振相关的模式偏差，以及光谱宽带单模传输和模式分布的结构照明将被研究。

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.