Characteristic features of light confinement and propagation over photonic crystal fibers

This work is concerned with features of light confinement and propagation over photonic crystal fibers (PCFs), which are classified on operating principles and geometry. Photonic band gaps and photonic crystals are considered, as well as the most interesting types of PCFs, their structure and applications are overviewed. The present paper deals with application of twisted PCF as a fiber optic wavelength filter that is able to be used for signal transmission at various wavelengths or signal sample transmission at certain wavelength depending on twist parameters. Here light reflection effect in PCF structure is described in terms of geometry optics in the basis of Snell’s law. The work represents overview of temperature influence on filling material condition and thus on refractive index value in PCF structure as well as perspectives of PCF using in various applications of fiber optics and photonics.