Theoretical And Experimental Researches Of Brillouin Laser Based On High Nonlinear Fiber

Brillouin fiber laser uses the stimulated Brillouin scattering effect(SBS)in fiber to provide gain and obtain single or cascaded Brillouin laser output,which has the characteristics of low threshold,fixed wavelength spacing,narrow linewidth and high light conversion efficiency.Multi-wavelength Brillouin Erbium-doped fiber laser combines nonlinear gain of the SBS with linear gain provided by Erbium-doped fiber has potential application value in the fields of all-optical communications and fiberoptic sensing.The theoretical and experimental researches of Brillouin laser based on high nonlinear fiber is developed in this paper.Coupling process of pump light and Stokes light in the first-order Brillouin fiber laser based on high nonlinear tellurite fiber is simulated.The effect on output performance of first-order Brillouin fiber laser caused by variation of pump power,fiber length and reflectivity at output is investigated.Brillouin erbium-doped hybrid fiber lasers(BEFL)based on high nonlinear optical fiber is studied experimentally.Based on linear and composite cavity structure,relationship between output characteristic parameters of the BEFL and factors such as Brillouin pump wavelength,pump power and cavity structure is studied.The main works are as follows:Firstly,the theory of SBS is introduced.The definition of the Brillouin threshold and the power coupling equations between pump light and the Stokes light in the fiber are given.The affect on output performance of first-order Brillouin fiber laser caused by factors such as pump power,fiber length and reflectivity of output coupler is investigated by using finite element method combine fourth-order Runge-Kutta algorithm and shooting method.Obtaining the optimized parameters.Secondly,by using single-mode silica fiber as Brillouin gain medium,through experimental analysis,the threshold pump power of BEFL with linear cavity are obtained at different Brillouin pump(BP)wavelengths.With the change of 1480 nm pump power,the output variation of high order Stokes is studied.By adjusting the tunable filter,the BEFL with linear cavity can be tuned within more than 30 nm range continuously.Thirdly,by using single-mode silica fiber as Brillouin gain medium,through experimental analysis,the threshold pump power of BEFL with composite cavity are obtained at different Brillouin pump(BP)wavelengths.With the change of 1480 nm pump power,the output variation of high order Stokes is studied.By adjusting the tunable filter,the BEFL with composite cavity can be tuned within more than 30 nm range continuously.