Design And Characteristics Study Of Large-Mode-Area Hybrid Waveguide Microstructured Fiber

Fiber laser plays an important role in the manufacturing industry, military and biomedical because of its high beam quality, small volume, high efficiency, fast heat dissipation. Large-mode optical fiber is considered to be the most effective way to solve to power limitation of fiber nonlinear effects and fiber damage when enhance the high-power fiber laser power. This paper proposes a novel large-mode-area hybrid waveguide microstructure fiber, and studies its fabrication technology and optical characteristics. The main contents are summarized as follows:The light guide mechanism of all-solid hybrid waveguide microstructure fiber are studied, considering of total internal reflection and band gap. The former is similar to the traditional step-index fibers and the latter model is explained by anti-resonant reflecting optical waveguide (ARROW).We designed a novel large-mode-area hybrid waveguide microstructure fiber and a row of germanium doped high refractive index rods are arranged periodically in the core and its cladding substrate considers of uniform silicon dioxide while the germanium-doped silica rod was inserted in the core of fiber. Based on Finite-Element-Method the opticalcharacteristics of large-mode-area hybrid waveguide microstructure fiber were investigated, i.e. Dispersion,effective mode area, bend loss, confinement loss.Based on the all-solid linear array structure fiber which was fabricated successfully in the laboratory previously, the fabricationtechnology of large-mode-area hybrid waveguide microstructure fiber were theoretically studied,including optical fiber preform and optical fiber drawing.This fiber can achieve regulation dispersion and can achieve zero dispersion at 1.06?m and its effective mode area can reach 360 ?m2 by adjusting the spacing and diameter of the high refractive index germanium doped rod. Furthermore, it can be achieved single-mode output at 1.31?m by using bend loss.