Theoretical And Experimental Research On Fiber Laser Performance Working At Different Temperatures

Due to the advantages of high conversion efficiency,good beam quality,compact structure,stable performance and so on,the high power fiber laser developes rapidly and has been employed in important applications,such as industrial processing,military defense and other fields.With the continuous expansion of the application field,in some scenarios that can not guarantee a good operating environment and working temperature control,it is urgent to adapt to more platforms,more occasions,stable operation in a wider range of working temperature.At present,most of the high power fiber lasers are considered to reduce the thermal effect through various thermal control technologies.Generally,they work at room temperature,and the research on high-power output at low temperature is less,which can not meet the application needs of wide temperature range.Based on this,the theoretical and Experimental Research on the effect of operating temperature on the output characteristics of fiber laser is carried out in this paper.1.Point out the influence of temperature on stimulated Raman scattering and mode instability in fiber laser.The research progress on the influence of temperature on fiber laser is reviewed.And the research significance of the influence of the working temperature on the output characteristics of the fiber laser is clarified.2.The existing steady-state rate equation model of fiber laser is introduced.Based on the analysis of the influence of temperature on the composition parameters and initial boundary conditions of the rate equation,the expression of physical quantities is improved according to the influence of temperature parameters,and the steady-state rate equation of Yb³⁺doped fiber laser considering the working temperature is established.3.The key optical fiber devices and laser system are studied.According to the characteristics and volume of the test object,the temperature control system is designed and the test platform is built to study and test the temperature characteristics.The experimental results provide a direct data support for the design,simulation and optimization of high-power and wide temperature operating laser.The experimental research method also provides a complete scheme for the device selection and testing of wide temperature laser.4.The scheme of 2k W wide temperature operation laser is designed,and the simulation analysis is carried out based on the See Fiber Laser fiber simulation software.A 2k W high-power fiber laser has been built and successfully realized the high-power output over 2k W in a wide range of operating temperature from-10?to 20?without forced heat conduction.5.Designed and built a fiber laser with a low TMI threshold,carried out a study on the TMI threshold within the wide operating temperature range of-10??20?.The results show that low temperature is beneficial to increase TMI threshold.