| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a fiber Bragg grating element, in which the ripple of amount of shielding produced in a used wavelength band is prevented or reduced, and to provide a fiber adaptor. <P>SOLUTION: The fiber Bragg grating element includes a core; a cladding provided at the outside of the core; and a plurality of chirped fiber Bragg gratings which are provided at least in the core, perform filtering to cutoff an optical signal entering an optical waveguide at a predetermined wavelength band, wherein at least two gratings are arranged to be separated from and facing each other, so composed to Bragg-reflect an optical signal having a wavelength close to 1650 nm, grating pitch becomes shorter as separated from the center of the facing gratings, and the distances between the facing gratings are 1.5 to 2.0 nm. <P>COPYRIGHT: (C)2011,JPO&INPIT</p> |
