Numerical analysis of fiber Bragg gratings with the asymmetry index profile in the transverse plane

摘要

The asymmetry index profile in the transverse plane, which could be induced during the writing of fiber Bragg gratings with UV side-exposure techniques, may cause the photo-induced birefringence, as was numerically evaluated by Kokou Dossou et al. But the impact of this photo-induced birefringence on the performance of fiber grating components remains to be determined. In this paper, we numerically analyzed this kind of impact by using a finite-element method with a full vectorial formulation and the coupled-mode equations. It shows how the birefringence affects the reflection spectrum, the group delay. This numerical method will be useful in designing and analyzing fiber gratings.