Editing Single-mode optical fiber (section)

==Quadruply clad fiber==
In [[fiber optics]], a '''quadruply clad fiber''' is a single-mode optical fiber that has four claddings.<ref>{{FS1037C}}</ref> Each [[Cladding (fiber optics)|cladding]] has a [[refractive index]] lower than that of the [[Fiber_optics#Principle_of_operation|core]]. With respect to one another, their relative refractive indices are, in order of distance from the core: lowest, highest, lower, higher. 

A quadruply clad fiber has the advantage of very low macrobending losses. It also has two zero-[[dispersion (optics)|dispersion]] points, and moderately low dispersion over a wider [[wavelength]] range than a singly clad fiber or a [[doubly clad fiber]].