Low-crosstalk active optical fiber with uniform pumping

The invention relates to a low-crosstalk active optical fiber with uniform pumping, the cross section of the optical fiber comprises a plurality of doped fiber cores (1) and a cladding area, the plurality of doped fiber cores (1) are arranged in a two-layer triangular structure and a hexagonal structure, the cladding area comprises quartz (2) and high refractive index rods (3) which are periodically arranged, and the quartz (2) and the high refractive index rods (3) are arranged in the cladding area. Wherein the high-refractive-index rods (3) are arranged into a hexagonal periodic structure, the high-refractive-index rod closest to the doped fiber core is removed, and the other areas of the cladding are made of quartz. According to the optical fiber, the problem of uniform absorption of the doped fiber core to the pump is solved, inter-core crosstalk of the multi-core optical fiber is reduced, and balanced gain amplification of a plurality of independent channels of a multi-core optical fiber amplifier is eff