Polarization dependent cladding modes coupling and spectral analyses of excessively tilted fiber grating

Abstract

We report on the detailed analyses of mode coupling from fiber core to cladding in excessively tilted fiber gratings (ETFGs). Cladding modes responsible for the typical dual peak pairs in the transmission spectrum of ETFGs are identified with phase matching condition, which suggests two set of dual peak pairs generated from coupling to cladding modes with even and odd azimuthal order. The polarization dependence of those dual peak pairs are also investigated by calculating the coupling coefficients of cladding modes for two orthogonal polarizations. With the calculated coupling coefficients, the measured polarization dependent spectra can be reproduced numerically.

Numerical Analyses of the Polarization Dependent Cladding Mode Coupling in Localized Fiber Bragg Gratings

“…It can be seen from Fig. 7b that, due to the quasi-degeneracy of EH/HE modes, their resonant wavelengths appear in pair [24], [25].…”

Fabrication and Characterization of Line-by-Line Inscribed Tilted Fiber Bragg Gratings Using Femtosecond Laser

“…Birefringence characteristics also presents in Ex-TFG. Thus, Ex-TFG is a good candidate for polarization-dependent sensing [ 9 , 10 ]. 45° TFBGs experience high polarization-dependent loss, which provides a method to realize an all-fiber polarizer [ 11 ].…”