Research On Fiber Coupled Pump Module Of Conduction Heat Sink Laser Diode Theoretically And Experimentally

High power fiber lasers with excellent beam quality, large power density, high power conversion efficiency, small footprint, compact, easy modulation, easy to use and free from maintenance and other notable features, have gradually replaced the solid lasers and gas lasers and are widely used in military, industrial processing, medical and space communications. Application development of this technology in future, however, is limited by the availability of compact, cost effective, high brightness and high reliability fiber coupled laser diode pump module.This paper was based on the laser material processing and military application of high power fiber lasers and fiber coupled diode lasers with the purpose of improving the fiber coupled diode lasers brightness. The main object is fiber coupled laser diode pump module. Having done a lot of surveys and analysis of the domestic and foreign technology routines, we decided to take conductively cooled high power diode laser bars routine to achieve the high brightness output of fiber coupled diode laser pump module.Efforts had been made to reduce the cost of the fiber coupled diode laser pump module through many experiments of package technology of diode laser bars. We summed up the key technical issues and briefly described the package processing. Finally the test parameters of self-packaging diode laser bar were shown. We analyzed the far-field characteristics of semiconductor laser array collimated through the fast and slow axis lens in parameter test. The result can guide the design and processing of the subsequent beam shaping and focusing systems.In this paper, beam focusing characteristic parameter values, which can evaluate the laser beam quality, was described in detail, so was the beam parameter production BPP expression in fast and slow axis of one-dimensional diode laser array. We introduced fiber coupling techniques of conductively cooled laser diode array theoretically and experimentally. According to the theoretical calculations, this routine can be coupled into fiber with core 200μm and NA0.22. In the experiment, we coupled into core 600μm and NA0.22 fiber with the output power 160.5W (The right prisms and beam shaping lens are not coated), the coupling efficiency 74% and the overall wall-plug efficiency exceeding 42.5%. Meanwhile, we also analyzed the reasons between theoretical and experimental difference, which provide guidance for the follow-up experiments.At the end of this paper, fiber coupled high power diode laser pigtail fiber bending experiment had been presented, combing with the analysis of propagation ray theory in cladding layer of multi-mode power delivery optical fiber, we found that transmission efficiency of bending fiber is determined by bending radius and bending length. Meanwhile, a new easy approach to judge the beam quality of fiber coupled laser diode by bending fiber was presented.