This graduation thesis deals with use of unconventional optical fiber with the intention of photonic crystal fiber. There are described types of photonic crystal fiber, their physical, optical and transfer characteristics. There is explained what are the photonic crystals, principle of their function and possible types of crystals. There are also detailed types of photonic fiber commonly used in the optical fiber branch. There is also explained photonic crystal fiber its structure a hierarchy of its types. In this thesis are described and demonstrated different kinds of photonic optical fiber and their use. There is demonstrated principle of one-dimensional periodical structure of Bragg fiber using simulation software. There can be seen graphical comparison of the simulated optical fiber core to commonly obtainable fiber. Outcome of this graduation thesis should be explanation of function of photonic crystal fiber and possibility of finding new type of fiber with optimal dispersion characteristics for use in fiber optics.