Optimal Design Of The High-energy Wavelength Tunable Tm-doped Raman Solition Fiber Laser

Recently,the fiber laser with emission around 2 ?m has attracted wide attention from researchers in industrial gas and environmental monitoring,laser communication and radar,polymer material processing,laser surgery and so on.Tm-doped Raman soliton fiber laser has become a research hotspot in recent years because it can produce high-energy near-transform-limit ultrashort optical pulses which wavelength range could beyond the gain bandwidth of Tm-doped fiber.The experimental research of Tm-doped Raman soliton fiber laser has been carried out,but the theoretical research needs to be further studied in detail.In this paper,the numerical simulation method is used to optimize the design of the Tm-doped Raman soliton fiber laser and the seed laser.The specific content and research results are as follows:1.The research progress of high energy Tm-doped pulse fiber laser,tunable Tm-doped pulse fiber laser and Raman soliton fiber laser are summarized,and their main applications are introduced.2.The generalized nonlinear Schrodinger equations of optical pulse propagating in optical fibers under different conditions are given.The multi-mode Raman response function used in this paper is introduced,and the step Fourier transform method used in numerical simulation in this paper is briefly described.3.The Tm-doped Raman soliton laser with chirped pulse amplification structure is studied and optimized by numerical simulation.The effects of high numerical aperture fiber length,double cladding Tm-doped fiber length,Tm-doped fiber length,seed pulse width and peakpower of seed pulse on Raman soliton pulse energy and central wavelength are studied respectively.By analyzing and optimizing,the Ramam pulse generation with the highest Raman soliton pulse energy is 23.43 nJ and the center wavelength tunable range is 1976-2414 nm are abtained.The seed pulse requirements of the Tm-doped Raman soliton fiber laser are also obtained.4.The seed laser of Tm-doped Raman soliton fiber laser is optimized by numerical simulation.The effects of single-mode fiber length,high numerical aperture fiber length,Tm-doped fiber length,filter bandwidth and output coupling ratio on the M factor of seed pulse,dechirped seed pulse width and peakpower are studied respectively.The seed pulse with M factor of 0.025,dechirped pulse width of 149.4 fs and peakpower of 59.562 kW are obtained.