Research On Pulsed Fiber Laser Based On Fe3O4 Nanomaterials

Pulsed fiber lasers are widely used in fiber optic communication,industrial processing,laser ranging,etc.High repetition rate ultrashort pulse lasers have become an important researcher in the field of lasers due to their narrow pulse width,high peak power and wide spectral range.The main method of obtaining ultra-short pulse laser with high repetition rate is laser mode-locking technology,including:Nonlinear polarization rotation technology,nonlinear ring mirror technology,saturated absorption technology,which uses saturated absorption technology to realize fiber-mode laser mode-locked pulse output is a research focus and hotspot in recent years.In recent years,the rapid development of nanomaterial science has greatly promoted the advancement of pulsed fiber lasers.The new optical materials used to realize laser pulse mode-locking mainly include carbon nanotubes,graphene,graphene,topological insulators,transition metal sulfides,etc.At the same time,the magnetic material of the ferroferric oxide is controllable due to the energy band gap,and the response time The short advantage plays an important role in the research of pulsed fiber lasers.In this paper,the ferroferric oxide nanomaterials are used as saturated absorbers.In the ring cavity optical laser,not only the Q-switched pulse with a center wavelength of 1530 nm is obtained,but also the dissipative soliton resonance phenomenon is observed,and the pulse width is 10 ns.The square wave pulse,and the output of the harmonic mode-locked pulse is realized on this basis.The progress of the passive mode-locked fiber laser with the ferroferric oxide as the saturated absorber has made great progress,which provides for the future research.Experimental studies provide a reference and provide reliable evidence for the application of ferroferric oxide in the field of lasers.The main work of this paper includes:First,the device is used to form a mode-locked device by using a saturated absorber of ferroferric oxide nanomaterials.In the erbium-doped ring cavity fiber laser,the phenomenon of dissipative soliton resonance is observed.The repetition frequency is 7.69MHz,and the pulse width is in the range of 10?20ns.The square wave pulse with the same pulse shape and constant pulse width has a corresponding maximum spectral width of 1.05 nm and maximum pulse energy of 1.032 nJ.The feasibility of the pulse-mode-locking scheme in the ring-shaped fiber laser is verinfied by experiments.Later research on mode-locked pulsed fiber lasers provides some technical support.Second,based on the ferroferric oxide saturated absorber,the harmonic pulse phenomenon was observed in the erbium-doped ring cavity fiber laser.By adjusting the polarization state of the laser in the cavity to control the phase difference between adjacent solitons in the laser cavity,the interaction between the soliton component and the non-soliton component in the pulse is changed,so that the soliton in the cavity is evenly distributed and harmonic pulses are generated..In the experiment,by adjusting the polarization control device in the laser,two to six-order harmonic pulses were observed at the laser output end,and the corresponding laser repetition frequencies were 15.38 MHz,23.07 MHz,30.76 MHz,38.45 MHz,and 46.15 MHz,respectively.According to the analysis of pulsed laser characteristics,the formation of such harmonics is related to the interaction between solitons in the cavity.The frequency difference between adjacent solitons is reduced,the solitons are close to each other,the frequency difference is increased.,and the solitons are far away from each other.The polarization state causes the two states to be mutually converted to achieve the purpose of soliton redistribution.It provides data support for the study of subsequent harmonic pulsed fiber lasers.Third,in the ring-cavity erbium-doped fiber laser,the ferro-conductor nano-material is used as the saturable absorber as the Q-switch.The Q-switched pulse with a center wavelength of 1530 nm is obtained.The pulse repetition frequency and width are respectively increased with the pump power.High and linear increases and nonlinearities decrease.The feasibility of using a saturated absorber of ferroferric oxide nanomaterial as a Q switch is demonstrated.