| 摘要 |
PROBLEM TO BE SOLVED: To make UV rays enter with a mode field diameter in a practical size, to reduce the size of the optical system for entering and emitting and to decrease the optical path length. SOLUTION: The fiber has a core region made of silica glass and formed in the cross section perpendicular to the axial direction, a clad region surrounding the core region and a fine structure formed in at least the clad region and containing a plurality of holes having a specified cross-sectional area in silica glass. The propagation mode of light at 400 nm wavelength is a single mode, and the core region and the clad region have the structure to propagate the light of the above wavelength. |
