Magneto-refractive characteristics and mechanism of erbium-doped silica fiber

The magneto-refractive characteristics of erbium-doped silica fiber (EDF) are of great significance in magnetic field sensing. The fiber doped with rare earth Er
³⁺
has a large magnetic moment and spin splitting, which makes a major contribution to the magnetic properties of the fiber. The refractive index of EDF in different magnetic fields was measured. The experimental results show that the refractive index of EDF decreases linearly with the increase of magnetic field. The magneto-refractive sensitivity of EDF is 3.21×10
⁻⁵
RI /mT, which is about 20 times higher than that of single-mode fiber. The magneto-refractive properties of silica fiber are enhanced by rare earth element Er
³⁺
.