| 摘要 |
PROBLEM TO BE SOLVED: To enlarge transmission loss of light within an inhibit band for waveguide of a core section.SOLUTION: This optical fiber type optical filter is equipped with: the core section 11 extending in a waveguide direction of incident light; and a clad section 12 extending in the waveguide direction and surrounding the core section 11, wherein the clad section includes a plurality of rods 13 having a refractive index higher than that of a background medium 14 of the clad section 12, and extending in the waveguide direction, which are provided with two fiber regions, a first PBGF region 15a and a second PBGF region 15a, arranged periodically in the clad section 12, and a light loss region 16 for coupling a waveguide mode in which light intensity is observed in the rods 13 of the clad section 12 of the first PBGF region 15a or the second PBGF region 15b with a radiation mode. The light loss region 16 is provided between mutually facing end surfaces of the first PBGF region 15a and a second PBCG region 15b. |
