This book highlights various recent developments in photonic crystal fibre technology and applications. The background information necessary to comprehend the findings described in optics. The book describes the linear characteristics of optical fibres and introduces the nonlinear optical phenomena ,explain a strategy for reducing bend losses in all-solid photonic band-gap fibres is described. describes a method for tapering photonic crystal fibres to decrease dispersion along their length, Solitons are compressed using nonlinear techniques. Also modifying the cladding structure of photonic crystal fibres may be utilised to create shorter supercontinuum generation.