Manufacturing technique of ultra-wideband high gain optical fibers and devices

A manufacturing technique of ultra-wideband high gain optical fibers and devices, comprising following steps:

• (1) manufacturing a gain fiber, wherein the gain fiber is a composite structural optical fiber comprising a core and a cladding, the core is composed of a plurality of sets of symmetrically distributed sector structures or a plurality of concentric ring structures, the plurality of sets of sector structures or the plurality of ring structures are composed of at least two kinds of rare-earth-ion-doped glass, luminescence centers of rare earth ions are located in different sector structure regions or ring structure regions in the core respectively, and the gain fiber has a gain coefficient larger than 1 dB/cm, and a gain bandwidth greater than 150 nm;
• and
• (2) constructing a fiber laser, comprising:
• using the composite structural optical fiber in step (1) as the gain fiber, selectively exciting the rare earth ions in different sector structure regions or ring structure regions in the core by controlling a shape of a pump light spot, and combining with fiber grating pairs to achieve tunable laser output;
• wherein the shape of the pump light spot is controlled by a mode selective coupler and/or a fiber polarization controller in step (2):
• wherein:
• for the gain fiber of which the core is composed of the ring structures, pump light is converted into a vector mode by the mode selective coupler, to generate ring pump light, and temperature or stress regulation is performed on the mode selective coupler to convert the pump light into the vector mode in a different order, so that the maximum values of light field are located in the ring structure regions doped with different rare earth ions, thereby exciting different rare earth luminescence centers to generate corresponding gains, and realizing laser switching between different wavebands;
• and central operating wavelengths of fiber rating pairs at both ends of the gain fiber are adjusted by a temperature or stress regulating device to implement that a wavelength of output laser is tunable in a specific waveband;
• for the gain fiber of which the core is composed of the sector structures, pump light is converted into a linear polarization mode with a two-lobed spot shape by the mode selective coupler, and an LP11 mode is controlled to rotate by the polarization controller, so that the maximum values of light field are located in the sector structure regions doped with different rare earth ions, thereby exciting different rare earth luminescence centers to generate corresponding gains, and realizing laser switching between different wavebands;
• and central operating wavelengths of fiber grating pairs at both ends of the gain fiber are adjusted by a temperature or stress regulating device to implement that a wavelength of output laser is tunable in a specific waveband.