In this letter, we report a new high attenuation fiber, whose cross section is a three-layered structure-the cobalt-doped core, the depressed inner cladding, and the outer cladding doped with cobalt in a ring. The proposed doping profile of cobalt ions both in the core and the cladding effectively attenuated the cladding modes to result in reduction of the modal interference. Enhancement of attenuation uniformity over a factor of three compared with prior techniques was achieved with the attenuation deviation less than 0.03 dB from 1250 to 1600 nm.
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Atomic and Molecular Physics, and Optics
- Electrical and Electronic Engineering