FIBER BRAGG GRATING ELEMENT, AND METHOD AND APPARATUS OF MANUFACTURING FIBER BRAGG GRATING ELEMENT

摘要

PROBLEM TO BE SOLVED: To provide a method of manufacturing a fiber Bragg grating element, in which a high cut off value exceeding 40dB is available in a wide band range with a simple structure, and to provide a method of manufacturing a fiber Bragg grating element in which the high cut off value is available and further a desired transmission loss is obtained.;SOLUTION: The fiber Bragg grating is characterized in providing: a core in which a plurality of gratings are formed of which the gap increases toward the central part from both end parts in the optical axis direction and the gap at the central part is larger than any widest gaps at parts other than the central part; and a clad of which the surface is provided with a shield part equivalent to the gap of the gratings at the central part.;COPYRIGHT: (C)2008,JPO&INPIT