Optimization Design Of MOPA High Power Fiber Amplifier

In recent years, with the development of fiber laser technology and optical fiber amplifier, more and more areas by high power fiber lasers and fiber amplifier to replace traditional lasers and amplifiers. At the same time, the optical fiber amplifier has been occupying the new market, people are constantly improving its performance. Master oscillator power amplifier (MOPA) will power smaller seed laser after one or multistage amplifier gain and high power output. Because the power of the seed laser is small, the output of the laser is easy to get better performance. By using MOPA structured fiber amplifier can be in high power laser output at the same time, do not change the excellent characteristics of the seed laser. The structure design of fiber amplifier has a wide application prospect is a hot research field of optical fiber amplifier. The research and the simulation analysis is conducted in this paper for the design and optimization of optical fiber amplifier MOPA structure, the main work is as follows:(1) Analysis of the working principle of rare earth doped fiber amplifier, starting from the rate equations, are derived and established all kinds of rare earth doped fiber amplifier of the numerical analysis model.(2) Through the analysis and solution of rate equations of the amplifier, influence of fiber amplifier performance of various factors, such as pump power, fiber length, rare earth doped and doped concentration.(3) The genetic optimization algorithm to find the optimization of MOPA fiber amplifier, in order to improve the output performance and optimized by genetic algorithm to simultaneously optimize the multistage amplifier pump power, fiber length and other parameters parameters, looking for the appropriate parameter values.The simulation optimization results of this paper can obtain the optimal output power in a certain condition by optimizing the pump power, fiber length, doping concentration and other parameters in the two stage amplifier of MOPA optical fiber amplifier, which has a certain practical value, and the research results have great reference value for the optimization of multi stage MOPA fiber amplifier, which provides some theoretical guidance for the design of the optical fiber amplifier.