Studies On The Fabrication Technology Of Photonic Lantern Combiner

The adaptive control of spatial mode of fiber laser based on the Photonic Lantern(PL)combiner is a newly developed technology which is expected to solve the mode instability of high-power fiber laser.In this paper,based on the requirements of the research on the adaptive control of the spatial mode in fiber laser system,we focus on the research of the fabrication of the core device—the photonic lantern combiner—based on Taper-fused Fiber Bundle(TFB),which provides the core component for the construction of the adaptive control system of the spatial mode based on the photonic lantern.The concept and application of the photonic lanterns are described in this paper,and the fabrication methods are analyzed and compared in detail.The principle of the adiabatic taper,the entropy increase and the optimizing of the geometric requirements are analyzed,and the design of the parameters of the photonic lantern is completed.Rsoft software is used to simulate the mode control of the photonic lantern.The simulation analysis is carried out for the influence of the cone angle parameter and the fusion alignment error on the output mode field,which provides the basis for the fabrication process control of the photonic lantern.In this paper,the design of 3×1,6×1 and 7×1 photonic lanterns are represented,and these three kinds of the photonic lanterns are fabricated by the TFB method and the coupling efficiency is tested.The experiment of mode decomposition based on the holographic grating is carried out for the 3×1 photonic lantern combiner.The transmission matrix of the photonic lantern is measured when the correlation of the nearfield and the far-field is high.Through the mode decomposition test,the fabrication process of the photonic lantern is fully verified,and the effectiveness of the mode control of the photonic lantern beam combiner is verified by the mode control test.For the development of fiber laser mode control system based on the photonic lantern,the problem of core device preparation is solved.