RARE EARTH DOPED OPTICAL FIBER

摘要

An optical fiber including: (i) a silica based, Yb doped core having a first index of refraction nj, said core comprising more than lwt % of Yb, said core having less than 5 dB/km loss at a wavelength situated between 1150 run and 1350 nm and less than 20 dB/km loss at the wavelength of 1380 nm and slope efficiency of over 0.8; and (ii) at least one silica based cladding surrounding the core and having a second index of refraction n2, such that n/> n2.