Download original image
Geometrical construction relating the effective group index ng-eff to the effective index neff of the fundamental mode of a fiber, with the dependence in normalized spatial frequency λc/λ. A double-slope line is drawn from where the tangent to the effective index curve crosses the ordinate axis, and the group index ng(λc/λ0) equates DS0(λc/λ0), as shown for λc/λ0 = 0.8, i.e., for λ0 = 1.25 λc. As in Figure 7, one easily sees that ng-eff is about equal to the refractive index of the core n1, in the practical domain of use of a single-mode fiber, i.e., λc < λ < 1.5 λc, or 0.67 < λc/λ < 1.
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.