Studt On Circular Cavity Fiber Laser With Narrow Line-width Output

The main characteristics of fiber laser is refers to using the optical fiber as the cavity at the same time act as the role of optical waveguide.Compared with the gas laser,solid laser and other lasers,fiber laser has good output beam quality,such as the advantages of small volume,compact structure,ease of integration,so widely used in industry,military industry,etc.Such as optical fiber communication,optical fiber sensing,laser radar,etc.In one of the fiber laser will be,pulse fiber laser,narrow line-width fiber laser,etc.Is described in this article the narrow line-width fiber laser with its low noise,high stability,good monochromaticity,plays an important role in industry,especially the application of military industry,as well as the needs of all kinds of scientific experiments.After a lot of reading at home and abroad of various universities and scientific research units,published in the literature,summarizes the current international mainstream of narrow line-width fiber laser technology and research level,and studied a new type of narrow line-width fiber laser.Its cavity structure USES a traveling wave ring cavity,and the fiber Bragg grating with standard to roughing cavity mode frequency,with the function of the saturable absorber to suppress cavity due to excessive light wave pattern density model competition,finally obtain the stable single-mode narrow line-width output.The specific content mainly includes the following:Studied the basic principle of laser are introduced and the standing wave line cavity,traveling wave ring cavity,and the characteristics of the simpler compound cavity.An important factor of affecting the fiber laser output beam quality are analyzed,including the types of doped ions,doping concentration,optical fiber empty space in the burning effect,cavity mode density is too large to jump,etc.In the effect of doping ions,double cladding fiber structure,and the transfer mode in the light field in the fiber,on the basis of the ring cavity laser has carried on the preliminary design,through analyzing the energy level structure of ytterbium ion and the absorption and emission spectrum of research,determines the required pump output wavelength;Respectively by MATLAB analysis the relationship between the output power and pump light incident power,output power and gain fiber length relationship and way of pump’s influence on the output power,to determine the optimal pump power,optimization of the optical fiber length,using the backward pump efficiency is higher.Has established the basic structure of ring cavity laser,on this basis,the pattern for the light of the circular cavity characteristics through the analysis,in order to get the required 1064 nm single frequency light waves,adopting the mode in fiber Bragg grating etalon filter.Due to the cavity mode density is higher,in order to obtain stable single frequency output,using saturable absorber frequency stabilization method,there is no pump cavity to join a gain fiber act as saturable absorber,to achieve stable output.Finally,accorded to the theory of the previous simulation,in which determined the parameters of the fiber laser.According to lab materials and laboratory equipments,We set up a circular cavity single-frequency narrow line-width fiber laser,and a experiment was carried out.Verify the previous analysis and design.