Applications Of Saturable Absorbers Based On The Two Dimensional Materials In 2μm Fiber Laser

Pulses fiber lasers have been widely applied in many important fields such as fundamental research,medical,industry and so on.It can be divided into two types: Q-switched fiber lasers which can generate pulses of microsecond or nanosecond and mode-locked fiber lasers which can generate pulses of picosecond or femtosecond.Compared with the traditional solid and gas lasers,fiber lasers possess advantages of robust structure,flexibility,perfect property of heat radiation and low cost.In order to accomplish the pulse generation of fiber lasers,people often use active or passive techniques.Obviouly,the passive techniques have advantages of simple structure,flexibility and stablilty.They are also the emphysis of this study,the main work of this thesis is listed as below: 1.Fabricated the uniform two dimensional nanomaterials including black phosphorus and WS2 by liquid phase exfoliation method,and characterized the physical properties of the two dimensional materials using atomic force microscope(AFM),scanning electronic microscope(SEM)and Raman spectrometer.2.Fabricated the two dimensional material based saturable absorber of low loss(~1.5 d B)through the optical deposition method accomplished with the loss monitoring.3.Adopt a 1550 nm fiber laser as the pump laser,thulium/holium doped fiber as the gain fiber,a wavelength division multiplexing,an optical isolator,a polarization controller and an optical coupler as the other components of the fiber laser.We successfully obtained the continous fiber laser at 2 μm wavelength.4.Applied the as prepared saturable absorber into the laser cavity,by adjusting the pump power and the polarization state of the laser cavity,stable Q-switched and mode-locked pulses were obtained.