Investigation On SBS Effect In The Chalcogenide Fibers

Other than ordinary silica fibers,Chalcogenide fibers have some unique properties.Chalcogenide microstructured optical fibers?MOFs?attract great attention for the properties of high Brillouin gain coefficient,wide Brillouin gain spectrum,and wide transmission window in mid-infrared waveband.Compared with Brillouin fiber lasers?BFLs?based on silica fiber,BFL based on chalcogenide MOFs can reduce the threshold pump power,increasing the cavity gain and output efficiency,and shorten thelength of fiber to reduce the complexity of the laser system.In this paper,the influence factors of the stimulated Brillouin scattering effect were analyzed by chalcogenide fibers,which provide a theoretical basis for the further study of experimental study in BFL.The numerical simulation of the optical field characteristics and acoustic field characteristics in the chalcogenide MOF with the core suspended by four air holes was performed,and the overlap factor was calculated to provide a theoretical basis for further study of the Brillouin gain.The main research content of this paper is as follows:First,we analyzed the factors affecting Brillouin Stokes frequency shift.The Stokes shift is affected by the pump wavelength and refractive index.By changing the pump wavelength or refractive index,the effect of the pump wavelength and refractive index changes on the Stokes shift was numerically simulated.Second,we simulated the optical field and acoustic field characteristics of high nonlinear chalcogenide MOF.The comsol and matlab softwares were used to simulate the optical field and acoustic field characteristics of the high nonlinear chalcogenide MOF with different core diameters and different materials filled with air holes.1.We simulated the optical field and acoustic field characteristics of MOF with different core diameters.Under the four or six holes microstructure,the optical field and acoustic field characteristics of the high nonlinear chacogenide MOF were simulated with the core diameters were 1.0?m,2.0?m,3.0?m,4.5?m,and 6.0?m,respectively.Then,we calculated their overlap factors,respectively.2.We simulated the optical field and acoustic field characteristics of the MOF with air holesfilled with different materials.The air holes were filled with water,alcohol,and CHCL₃,respectively.Simulated the optical field and acoustic field characteristics of the MOF in each case.