Research Of New Material-based Passively Mode-locked Fiber Laser

Passively mode-locked fiber laser has many advantages such as high efficiency,compact structure,and good heat dissipation performance,besides it can achieve ultra-short pulse with high peak power.So that it has a wide range of applications in nonlinear optics,microwave photonics,high-speed optical communications,machining,biomedical engineering and other fields.With the appearance of new materials such as carbon nanotubes,graphene,topological insulators and transition metal sulfides,mode-locked fiber lasers based on new materials have also been rapidly developed and have become one of the most important research topics in the field of laser technology in the world.In this thesis,erbium-doped mode locked fiber laser based on tungsten disulfide,SWCNT-based dispersion-managed erbium-doped mode-locked fiber laser,SWCNT-based ytterbium-doped mode-locked fiber laser are studied theoretically and experimentally,the main contents are as follows:1.A balanced twin-detector is set up and be utilized to study the nonlinear absorption characteristics of single layer tungsten disulfide.Then a passive mode locked erbium-doped fiber laser based on SWCNT is set up,which generates stable traditional soliton and dissipative soliton of L-band when the dispersion is changed.Besides,a new program is proposed for generating ultra-short pulse by putting a Faraday rotating mirror is traditional fiber laser and the corresponding numerical simulation is completed.2.An erbium-doped mode-locked fiber laser based on SWCNT is set up whose dispersion is-0.049 ps2,stable traditional solitons are output with central wavelength of 1565 nm,spectral width of 6.75 nm and pulse duration of 590 fs.The intra-cavity dispersion is managed by adjusting the length of the standard single mode fiber(SMF-28)and dispersion compensation fiber(DCF3)in the cavity,and the variation of spectral width and pulse width with dispersion in the near-zero negative dispersion region was observed and summarized.The dispersion is changed to 0.138 ps2 by adjusting the length of DCF3,stable dissipative solitons pulses are output with central wavelength of 1563 nm,spectral width of 10.7 nm and pulse duration of 24.2 ps.3.A ytterbium-doped mode-locked fiber laser based on SWCNT is set up and stable dissipative solitons is output when the dispersion of all fiber in the cavity is normal.The pulse duration is 440 ps,the wavelength is 1041 nm and the spectral width is 1.54 nm.Then,the form and evolution of dissipative solitons in all-normal-cavity is analyzed by numerical simulation.