| 摘要 |
An optical fiber (200) comprises an optical fiber axis (A-A); a core (205) extending along the axis, the core being made of a first, undoped material having a first refractive index; and a cladding (210) coextensive to and surrounding the core. The cladding comprises a background matrix (220) made of the first material, and has a plurality of holes (215), formed in the background matrix, extending parallel to the fiber axis, arranged around the core in substantially concentric rings, and filled with a second material having a second refractive index lower than the first refractive index. The number of said rings of holes is two or three, an average distance (Lambda) between the holes is of at least about 6 µm, a ratio between an effective radius (reff) of the core and the average distance between the holes is of at most about 1, and a ratio between an average dimension (d) of the holes and the average distance (Lambda) between the holes is of at least about 0.5 |
