Abstract: The present invention relates to optical fibers and especially to optical fibers having microstructures in core and/or cladding region(s). The fibers may be utilized for dispersion compensation and non-linear applications.

Abstract: Micro-structured optical fibers are improved with respect to increasing the dispersion, both to large negative or large positive values, in a first fiber design in which the fiber has a micro-structured core region being surrounded by a micro-structured cladding region with cladding features being large compared to a predetermined wavelength of light, which can be guided through the fiber. Preferably, the effective index of refraction of the core region, Nco, is larger than the effective index of refraction of the cladding region, Ncl, at the predetermined wavelength of light. It is further preferred that the refractive index of one or more of the core features is lower than the refractive index of the core material.