Light Propagation through Photonic Crystal Fibers (PCF) is the main focus in this book. Nowadays Photonic Crystal Fibers are supposed to be new advancement in the field of optical communication. Research is being conducted in this field to study the transmission properties of PCF and how these properties can be improved to get an optimum design for PCF for different applications. In this book, light has been passed through a PCF which has low confinement loss and dispersion properties. The Mathematical Model for light propagation through PCF has been presented. The purpose of a design with low confinement loss and dispersion is to find the application of PCF in Wavelength division multiplexing system in which low loss and dispersion is required.