Simulation study on the influence of fabrication process defects on erbium-doped phase-shifted fiber grating

The process defects involved in phase-shifted fiber grating fabrication by the scanning exposure method are analyzed, which include phase shift impreciseness, stained point on phase-mask, unstable UV energy, non-uniform motion of scanning platform and so on. And the fabrication process defects of are divided into three destabilization situations: πphase-shift deviation, random phase shifts, and grating chirping. The mechanical simulation of phase-shifted fiber grating and distributed feedback fiber laser based on the coupled-mode theory and transmission matrix methods are carried out to analyze the effect of disturbance-induced defects during fabrication on the spectrum of phase-shifted fiber grating and the lasing performance of distributed feedback fiber laser.