| 摘要 |
PROBLEM TO BE SOLVED: To provide a comparatively simple method for manufacturing a fiber grating that has a superior long-term reliability. SOLUTION: The method includes a process where an optical fiber 10 having a core 12 and a clad 14 is prepared, a process where the first area 10a of the optical fiber 10 is seletively heated to the first temperature above a glass transition temperature range, a process where the first area of the optical fiber 10 so heated is cooled down to the second temperature below a glass transition temperature range to selectively lower the density of the first area 10a of the optical fiber 10, so that the refractive index of the first area 10a is made lower than that of other areas. Then, the fiber grating in which plural first area 10a are periodically formed is manufactured. |
