According to the requirement of quasi-distributed high temperature sensor based on fiber Bragg grating(FBG),preparation method of the FBGs with different periods is studied by using the femtosecond laser phase mask combined with fiber pulling.Periods of the FBGs are controlled by changing the stress applied to the fiber during femtosecond laser irradiation,then the quasi-distributed high temperature sensor based on the FBGs with different Bragg wavelengths is obtained.Temperature response parameter of the F...