Design And Study Of Gain-guided And Index-antiguided Fiber

Gain-guided,index-antiguiding(GG-IAG) fiber as a new structure of large-mode optical fiber, with large core diameter, single-mode laser output characteristics, It proposed a new solution to overcome the bottleneck problem of high power fiber lasers. In this paper, the characteristics of Er3+Yb3+-codoped GG-IAG fiber have been studied. In theory part, optimizing the optical fiber structure, fiber parameters, end-pumped way; In experimental part, melting fiber material. The specific contents are as followsIn theory part, first,based on the GG-IAG fiber single-mode transmission theory, establishment of Er3+/Yb3+co-doped fiber amplifier gain characteristics of GG-IAG transport equation model, The effects of Er3+doping concentration, core and cladding rate difference|Δn|, signal power and the fiber length on Er3+/Yb3+-codoped GG-IAG fiber amplifier gain performance were analyzed by using variable length the runge-kutta method. Second, establishment of Er3+/Yb3+co-doped fiber laser gain characteristics of GG-IAG transport equation model, numerical analysing distribution of pump power, the laser power, laser output power, slope efficiency and Influence of reflectivity on output power. Then, the GG-IAG optical fiber pump efficiency is calculated, including core pumping and cladding pumping, a feasible method to improve the efficiency of single end-pumped, can be used in the future Er3+/Yb3+co-doped pumping technology.In experimental part, the high-temperature melting process preparation of higher purity, lower loss of Er3+/Yb3+co-doped phosphate glass materials was melted, testing the Er3+/Yb3+co-doped phosphate glass physical and optical features, Including fluorescence spectra, transmittance, absorption spectra, fluorescence lifetime, Theoretical calculation of the Yb3+and Er3+absorption cross section, stimulated emission cross section area, absorption and fluorescence linewidth etc., based on optical parameters obtained by testing and calculating, according to the establishment of the Er3+/Yb3+co-doped fiber amplifier gain characteristics of GG-IAG transmission equation model, calculating the amplification performance of Er3+/Yb3+co-doped phosphate glass gain material.