Thulium-holmium coaxial doped optical fiber for 2.1 [mu] m laser single-mode efficient amplification

The utility model discloses a thulium-holmium coaxial doped optical fiber for 2.1 [mu] m laser single-mode efficient amplification. The thulium-holmium coaxial doped optical fiber comprises a holmium-doped fiber core inner core; the thulium-doped core outer circular ring tightly wraps the holmium-doped fiber core inner core, and the holmium-doped fiber core inner core and the thulium-doped core outer circular ring are jointly integrated into an optical fiber core; the inner wrapping layer tightly wraps the outer part of the thulium-doped core outer circular ring; the outer cladding layer is tightly coated outside the inner cladding layer; and the outer part of the outer cladding layer is coated with the coating layer. According to the thulium and holmium coaxial doped optical fiber for 2.1 [mu] m laser single-mode efficient amplification, a thulium and holmium ion partition coaxial doping mode is adopted instead of a conventional co-doping mode, so that the influence of energy transfer up-conversion during fi