Method to reduce birefringence and polarization mode dispersion in fiber gratings

摘要

Side-writing a refractive structure, such as a grating, into a waveguide results in an asymmetry in the induced refractive index change and a preferential orientation of dipolar defects, that leads to birefringence and polarization mode dispersion (PMD) in the refractive structure. Illumination of the structure to photo-reduce and to randomize UV-absorbing defects in the waveguide results in a reduction of the birefringence and the PMD.