| 摘要 |
PROBLEM TO BE SOLVED: To solve the problem that a method for applying a refractive index aligning agent on outer peripherals of a clad layer is taken for the purpose of suppressing clad mode loss of fiber grating, however, alignment of the refractive index is difficult and reduction of low clad mode loss is difficult. SOLUTION: In the fiber grating formed by adding a material 1 having an effect of raising photosensitivity and the refractive index to a core layer, adding the material 1 and a material 2 having an effect of raising the photosensitivity and lowering the refractive index to the clad layer together and further applying the refractive index aligning agent on the outer peripherals of the clad layer, the low clad mode loss can be reduced by making adding quantity of the material 1 at a center part of the core layer smaller than the maximum adding quantity of the substrate 1 of the core layer. COPYRIGHT: (C)2004,JPO |
