Research On Equal Energy Three-beam Splitting Method And Welding Simulation Based On Fiber Laser

The fiber coaxial coupler is a connector that couples the laser beam of the semiconductor laser into the transmission fiber through a microlens.It is composed of a microlens,an optical fiber,and a packaging shell.It is one of the important components in optical communication system.In order to achieve long-term stability of the optical path,after aligning the coupling optical path of the microlens,semiconductor laser and optical fiber in the coaxial device,it is necessary to use at least three lasers to weld the package shell simultaneously and the frame in the coaxial device symmetrically.The three laser beams need to be welded at the same time,and the energy difference of the three laser pulses is within 2%.Otherwise,the stress will cause device deformation and deviation of the optical path,which will seriously affect the efficiency of coupling the laser beam into the optical fiber.At present,the three-beam light source system that realizes the above welding generally uses lamp-pumped solid-state lasers,which have high maintenance costs,poor beam quality,and large light spots.With the continuous development of optical fiber communication,optical communication-related devices are developing in the direction of more miniaturization,The problems of lamp-pumped lasers in precision welding are gradually emerging.In addition,the existing three-beam light source system uses optical lenses plated with a certain transmittance and reflectance to split the laser beam.The flexibility is insufficient,and it is not easy to improve and eliminate the unequal energy of the laser to the workpiece end.Welding has an adverse effect.This paper proposes the use of modulated continuous fiber lasers instead of pulsed lamp-pumped solid-state lasers to achieve precision welding of optical communication devices,and uses acousto-optic Bragg diffraction to replace the beam splitting of coated lenses,and divide a laser beam into three beams of equal energy.This new type of fiber laser-based three-beam laser welding program has advantages over the existing pulse lamp pumped three-beam welding program: low power consumption of the equipment,maintenance-free,high welding efficiency,good solder joint quality,and three-beam The splitting ratio can be adjusted electronically.The main innovations of the paper are:First,based on the continuous fiber laser,through the analysis of acousto-optic interaction,the advantages and disadvantages of different acousto-optic devices and methods for laser modulation and beam splitting are analyzed and evaluated.The technical route of double acousto-optic beam splitter for three-beam splitting is adopted,and the influence of unequal energy caused by various loss and sound field distribution in the system is analyzed,and corresponding dynamic adjustment and compensation measures are proposed.Secondly,for the dynamic process of fiber coaxial device welding,the theoretical model and dynamic process of laser welding fiber coaxial device are established and simulated,and the light source parameters are analyzed from the two cross sections of the coaxial device.The influence of fiber lasers provides a basis for the feasibility of replacing lamp-pumped lasers with fiber lasers.Finally,based on the design scheme of the three-beam laser welding system,using a1500 watt continuous fiber laser as the light source,a three-beam experimental system prototype was built to verify the control method of the system and other energy.And the laser welding model guides the system Improvement and control.