| 摘要 |
PROBLEM TO BE SOLVED: To overcome the problem that in the case of a fiber for laser amplification comprising a light-propagating medium, in particular, a double clad fiber having a primary clad disposed around the core and further having a low refractive index region disposed as extended around the clad and in the longitudinal direction of the fiber, for example, a so-called holey fiber having holes as the low refractive index region, when the end face of the fiber is subjected to optical polishing and then to heat treatment, the end face of the low refractive index region is exposed to an external fluid, which induces changes in the refractive index of the low refractive index region (for example, if the low refractive index region is composed of holes, water flows into or is adsorbed to the holes by a capillary phenomenon and badly deteriorates the amplification characteristics of the fiber). SOLUTION: After the end face of the low refractive index region is sealed, the fiber is cut and polished to manufacture a fiber. By polishing, the end face of the fiber makes a given angle with respect to the plane perpendicular to the longitudinal direction of the fiber. COPYRIGHT: (C)2005,JPO&NCIPI |
