Research On All-solid Photonic Crystal Fiber And Its Application In Fiber Laser

Fiber laser has more advantages such as high beam quality, high coupling, high efficiency, fastheat dissipation, low cost and simple structure. The laser with traditional single mode fiber isdifficult to enhance the output power due to nonlinear effect and thermal damage mechanism.Photonic crystal fiber becomes a hot spot because of flexible structure and its excellent properties.In this paper, we proposed a novel all-solid square-lattice Yb3+-doped photonic crystal fiber, thestructure and properties of the AS-PCF are investigated by Finite Element Method combined withMATLAB. By intentionally designing the position of defect and optimizing the sizes of B2O3-dopedrods, the mode area of fundamental mode at1060nm is4405μm2when=25μm, d1/=0.5,ns=1.460, n0=1.452, also the PCF have the properties of single-mode operation and low bendingloss. The PCF can support single-mode operation for the bending radius larger than8cm.The fiber we designed in this paper is used in fiber laser. The output properties of the fiber laserare investigated based on the rate equations and transmission equations. The slope efficiency is90.57%when R1=0.99，R2=0.13，L=10.6m，N=1.02×1025/m3. The relationship between fiberstructure and properties is also investigated through the mode area. The best mode area is3520μm2.The conclusion provides theoretical support for the design of gain fiber of the fiber laser.