Propagation characteristics of dual-mode elliptical-core optical fibers

Abstract

Propagation characteristics of dual-mode elliptical-core fibers are obtained by using a perturbation approach. It is found that for very high values of core aspect ratios (a/b > 2.3), the maximum possible value of the V parameter in such fibers is decided by the cutoff of the LP(21)(even) mode instead of the LP(11)(odd) mode. Further, as the core ellipticity increases, unlike the polarization birefringence, the birefringence between the LP(01) and the LP(21)(even) modes decreases and the V value, at which the LP(01) and LP(21)(even) modes have the same group velocities, moves toward the LP(21)(even) mode cutoff.