Investigation Of 1.55 μm Er3+/yb3+ Co-doped Double-clad Fiber Laser

Er³⁺/Yb³⁺ codoped double-clad fiber lasers are more excellent photon sources than conventional fiber lasers, and they have very wide promising applications in modern communication system operating at the 1.55μm band. In this dissertation, the theoretical and experimental investigations of Er³⁺/Yb³⁺ codoped double-clad fiber lasers are presented. The main subjects are as following:1. Theoretical studies on Er³⁺/Yb³⁺ codoped double-clad fiber lasers in DBR configurations have been presented. Theoretical models of Er³⁺/Yb³⁺ codoped double-clad fiber lasers in DBR configurations are developed based on rate equations and power propagation equations. The characteristics of Er³⁺/Yb³⁺ codoped double-clad fiber lasers in DBR configurations are numerically studied using Rounge-Kutta method with MATLAB. The relationship between the output characteristics of the fiber laser and the parameters which include the pump power, the reflectivity of the output mirror, and the length of Er³⁺/Yb³⁺ codoped double-clad fiber, are discussed.2. Theoretical study on Er³⁺/Yb³⁺ codoped double-clad fiber lasers in MOPA configurations has been presented. The characteristics of Er³⁺/Yb³⁺ codoped double-clad fiber lasers in MOPA configurations are numerically studied using Rounge-Kutta method with MATLAB. The relationship between the pump power, signal power, the fiber length and the Gain, the Noise Figure of the fiber amplifiers is discussed, and the relationship between the above mentioned parameters and the output power of fiber laser is also discussed.3. Experimental study on the output power, the spectral properties and the time-domain stability of Er³⁺/Yb³⁺ codoped double-clad fiber lasers in DBR configurations has been presented. In the optimum condition, the maximum output power of 4.8W is obtained at 1550nm with a slope-efficiency of 51.5%, a light-light efficiency of 47.87%, and a 3dB bandwidth of about 0.02nm.4. The output power and the spectral properties of Er³⁺/Yb³⁺ codoped double-clad fiber lasers in MOPA configurations are demonstrated experimentally. The maximum output power of Er³⁺/Yb³⁺ codoped double-clad fiber lasers is 1.16W at 1547.8nm, and the Gain of the fiber amplifiers is 30.7dB.