Research On High-power Semiconductor Laser Beam Combiner Technology And Application

Facing the market prospects of laser processing, it is widely used in metallicmaterial welding, cladding, surface hardening for the industrial sector, taking intoaccount that the semiconductor laser is different from other types of high-powerlasers in its volume and small weight, high efficiency, maintenance-free, low cost,and the shorter wavelength is the characteristics of the metal material of a highabsorption band. So this paper integrates a laser machining light which selected asemiconductor laser. To achieve high quality and wide range in laser processing,light source must satisfy two important indicators, which are high power and highbeam quality. To solve this problem, this thesis has integated beam shaping, beamcombiner and heat dissipation technology of semiconductor laser deeply. Beamshaping can effectively improve the quality of a semiconductor laser beam, beamcombiner technology can exponentially increase the total power of thesemiconductor laser, heat dissipation technology can guarantee the service life ofsemiconductor laser. By studying these techniques semiconductor laser is advancedits application in the field of laser processing.The paper has respectively done system lab investigation on cm-bar combinerand single emitter combiner，and has done design simulation on mini-bar beam.Atthe same time according to different types of combined beams, their heat dissipationtechnology is studied respectively. The main work content and the results were asfollows:(1) Under conditions of large channel industrial cooled, cm-bar as alight-emitting unit, making use of space beam combiner, polarization beam combiner and the wavelength beam combiner technology together,808,880,938,880nm wavelength of four band light source are designed. Eventually a2218Wfiber-coupled module is developed, the fiber core diameter is only600μm, thenumerical aperture NA is equal to0.22, a high power and high beam quality of thelaser output is achieved. The BPP of Fast and slow axis is only20.5mm.mrad x23.5mm.mrad. The technical indicators currently have not been reported.Considering the slow axis of beam quality of mini-bar is less then half ofcm-bar, the method of using mini-bar as light-emitting unit is proposed. using twowavelength of915nm and976nm,500W light source which satisfies with200μmfiber is designed.(2) The808nm single emitter as a light-emitting unit, using space beamcombiner and a polarization beam combiner combination, the arrangement isdesigned as fixed ladder, the fast and slow axis of single-tube is collimated throughthe micro-lens to reduce each luminous point pointing error, increase the brightness,finally102.4W output the optical fiber coupler module is developed, the optical fibercore diameter is200μm, the numerical aperture NA is equal to0.22, the couplingefficiency is greater than85%.(3) For hundreds of watts single emitter combiner module, a use of anembedded heat pipe and TEC air-cooling method is proposed. According to the heat-coupling flow field to calculate, thermal coupling model of take thermal devicesand laser heating devices is established. Through ANSYS software simulation andfrequency red shift measuring method of experiment, the feasibility of theexperiment is verified. Finally a hundred of watts-class solid-state and smallair-cooling system module whose thermal resistance is less than0.254℃/W isdeveloped. And two invention patents have been applied, two articles have beenpublished(4) For the characteristics of2kw cm-bar combiner module who has the highintegration and high heat flux density, big channel water cooled heat dissipationstructure is used, according to the power of heat dissipation, the parameters ofcooling water flow rate, inlet temperature, and water pipes size are optimized. By using ANSYS software simulation, when ionized water flow rate is17.1L/min, feedwater temperature is22℃, the differential pressure is33581pa, the maximaltemperature of surface of water cold plate is no more than31℃. According to the"red shift frequency method", the effect of big channel water cooled heat dissipationis measured and is basically consistent with simulation results. The kilowatt-classbig channel water cooling plate cooling module is developed.