| 摘要 |
An optical fibre (1) comprises a core (2) and a cladding (3) that includes an inner cladding region (3a) with a refractive index that is photosensitive to UV light, surrounded by a non-photosensitive outer cladding region (3b). Refractive index gratings can be written into the cladding region (3a). Also, the refractive index of the inner region (3a) can be altered by exposure to UV light to achieve mode matching at a splice between fibres with different core diameters. An optical fibre laser is disclosed with integral refractive index gratings (33, 34, 36) in the cladding of a fibre with an optically active core. |
