Investigation Of LD Pumped All-fiber Er/yb Codoped Fiber Laser

Er3+/Yb3+ co-doped fiber lasers, as a new-pattern laser source applicable to all-fiber communication network and WDM System, have been paid great attention and developed rapidly since later 1980s. In this dissertation, theoretical and experimental investigations of Er3+/Yb3+ co-doped fiber laser are presented systematically.1. Basic principles and design philosophy of Er3+/Yb3+ co-doped fiber lasers are globally summarized. Properties and variety of double-clad fiber, cavity structure of fiber laser and pumping mode are discussed. Level structure and radiation theory of Er3+/Yb3+ system is analyzed. The theoretical model of Er3+/Yb3+ co-doped fiber laser is established based on rate equations for the atomic populations and power propagation equations.2. Theoretical simulation on working characteristics of Er3+/Yb3+ co-doped fiber laser in steady state is made using Rounge-Kutta method with Matlab. The relationship between the pump power, the fiber length, the reflectivity of the output mirror, the doping ratio of Yb3+ and Er3+ and output characteristics is discussed, which provides the theoretical basis for optimizing the fiber laser.3. Experimental studies on Er3+/Yb3+ co-doped fiber laser are presented. Three kinds of all-fiber DBR lasers are designed and put up with different parameters. Comparative study on the spectrum properties, power properties, and time-domain properties of them are carried out, experimentally. In the optimum condition, the maximum output power of the fiber laser is 2W with a slope-efficiency of 53.8%, and the measured lasing central wavelength and 3dB bandwidth are 1550.8nm and about 0.02nm, respectively. Furthermore, the experiment results validate the correctness of the theoretical study.