The Theoretical And Experimental Research Of Mid-infrared Raman Fiber Laser

Lasers in the mid-infrared band of 2～5μm have special applications in defense,medical and communication.Raman fiber lasers are a hot topic in fiber laser research in recent years.They have the ability to output laser light at any wavelength in the fiber transmission window.However,the current operating wavelength of the mid-infrared Raman fiber laser covers only 2 to 2.4 μm and 3 to 3.8 μm,and the output power is only wattage.In this paper,theoretical and numerical studies are carried out on mid-infrared Raman fiber lasers based on soft glass fibers.The main research contents are as follows:1.Based on the theory of nonlinear optics,the energy transfer model in Raman fiber laser is established.The accuracy of the model is verified by comparison with the results in the reference.The simulation of the tellurite fiber Raman fiber laser is carried out by numerical simulation to study the impact of the pump power and fiber length on output characteristics.2.The Raman fiber laser experiment was carried out using two tellurite fibers with core diameters of 3μm and 7μm respectively.By controlling the pump control voltage,pulse width,revisiting the spectral output,changing the parameters to suppress spectral broadening and high-order Raman light to obtain higher first-order Raman optical power.3.Established a model of fluoride fiber and tellurite fiber random distributed feedback fiber laser through theoretical analysis,and derive the relationship between Rayleigh backscattering coefficient and fiber scattering loss.The laser parameters such as fiber length and pump power were optimized by numerical simulation to verify the feasibility of realizing random distributed feedback mid-infrared fiber laser based on fluoride fiber and tellurite fiber.