MULTICHANNEL FIBER GRATING, MULTICHANNEL FIBER GRATING MANUFACTURING APPARATUS, AND MULTICHANNEL FIBER GRATING MANUFACTURING METHOD

摘要

To provide an optical fiber having a multichannel, spiral long-period fiber grating.SOLUTION: A fiber grating 1 includes a core 2 including a grating part 4 having a fiber grating with at least two mutually different channels, and a clad 3 formed around the core 2. The fiber grating is formed by twisting the grating part 4 of the core 2 with a light axis of the core 2 as a rotation center. Accordingly, since a fiber grating in which a refractive index changes spirally is formed in the fiber grating 1, distribution of a refractive index for achieving multiple channels can be formed precisely. Consequently, the multichannel fiber grating 1 can be achieved.SELECTED DRAWING: Figure 1