Performance Optimization Of Thulium Doped Fiber Laser Based On Genetic Algorithm

The Tm-doped fiber laser can output 1.7?2.1 ?m eye-safe band laser.It has some excellent features such as simple structure,good output characteristic and low requirements for working environment.It has been widely used in biomedical field,communication and remote sensing field,optical field and military field.It is of great significance in the research and application of single-mode fiber lasers with high output power and high slope efficiency.How to obtain excellent performance Tm-doped fiber laser is a hot issue in the field of fiber laser.In this paper,genetic algorithm is used to optimize these parameters that affect the performance of Tm-doped fiber laser.The purpose of optimization is to obtain the Tm-doped fiber laser that has the characteristic of high output power and high conversion efficiency.The main contents of this paper are as follows:(1)A ring cavity model of Tm-doped fiber laser based on the pump method of 3H6? 3H4 was established.The influences of pump power,fiber length,fiber core cross-sectional area and doped concentration on output characteristic of Tm-doped fiber laser were analyzed.(2)The parameters of genetic algorithm optimized for Tm-doped fiber laser are analyzed.The computing flow of five genetic algorithms,such as basic genetic algorithm,sequential selective genetic algorithm and dynamic linear transformation genetic algorithm,was established.The performance of algorithms were analyzed.These provide a theoretical basis for the performance optimization of Tm-doped fiber laser.(3)The relationship between the output characteristic and the structural parameters of the Tm-doped fiber laser was analyzed,and the structural parameters of the Tm-doped fiber laser were optimized.The results show that the optimal fiber core cross-sectional area and the optimal pump power of the Tm-doped fiber laser are 4.760×10-11 m2 and 97.3 W respectively at the doped concentration of 7.5×1025 m-3.The optimal fiber length is about 19.6 m.In this case,The Tm-doped fiber laser has an output power of 26.4 W and a slope efficiency of 27.2%.