Patent ID: 7171078

Claim:
A method, for fabricating super structure fiber Bragg gratings having multiple phase shift portions formed in positions depending on a code type; the method comprising: scanning a photosensitive optical fiber with ultraviolet laser light in a longitudinal direction of the optical fiber by means of a phase mask method, thereby forming a periodic refractive index modulation structure in a core of the optical fiber in the longitudinal direction; and instantaneously moving a phase mask used in the phase mask method by a predetermined distance in the longitudinal direction each time a radiation position of the ultraviolet laser light reaches each of predetermined positions in the middle of the scanning step using the ultraviolet laser light, thereby forming the phase shift portions in the periodic refractive index modulation structure formed in the core of the optical fiber, wherein the predetermined distance in the instantaneously moving step is smaller than a half a period of diffraction gratings of the phase mask.