Abstract:Agrawal G P and Turan Erdogan models of analyzing phase-shifted fiber grating are compared, the numerical calculation results show that the former is suit for homogenized phase-shifted grating, the latter is suit for all kinds of phase - shifted gratings. Multip le-thin films’model can be suit for all kinds of phase - shifted gratings’study, calculation accuracy satisfies design demand when slice of thin film is 20.