The Study On Theory And Experiment Of Ytterbium-doped Photonic Crystal Fiber Laser

Photonic crystal fiber can effectively reduce the nonlinear effects and thermal effects which the high-power fiber laser haved brought. And photonic crystal fiber laser also can maintain good beam quality to solve the problem that conventional fiber laser can not solve. In this paper,We give a deep study for Yb3+-doped photonic crystal fiber laser in both theory and experiment. The main subjects were as follows:1.Firstly, it briefly introduced the characteristics of photonic crystal fiber laser, and there was an overview of development of foreign and domesticYb3+-doped photonic crystal fiber laser, the main applications and the development were reviewed, and finally there was an overview of the contents of this paper.2. Secondly, there is a brief description on basic theory of the doped photonic crystal fiber laser; it describes the Yb3+ ion energy level structure, spectroscopic properties and characteristics of stimulated emission; it summarized and explained the light-guided mechanism of photonic crystal fiber and the refractive index guided photonic crystal fiber characteristics and advantages were overviewed.3. Thirdly, the theoretical mode of Yb3+-doped photonic crystal fiber laser was established. wave equation was drived from Maxwell's equations, the transmission characteristics in the optical fiber was drived, And according to the conclusions derived, comsol software was used to simulate the distribution of schema with light pattern in the transmission mode; According to rate equation theory, the power transmission equation of photonic crystal fiber laser was derived and the numerical simulation was done by using Matlab, and the impact on the laser output further of power distribution of the laser and pump light, threshold, the length of gain medium, slope efficiency,output transmission and pump means were introduced.The theoretical basis was provided for optimal design of the experiment.4. At last, the experiment of Yb3+-doped photonic crystal fiber laser with Fabry-Perot cavity was carried out. The maximum output power obtained was 26.61W. The slope efficiency was 41.3%. The experimental results and some factors were reasonably analyzed, and then some ideas and suggestions were presented.