摘要
450 nm蓝光波段半导体激光光源凭借其独特的波长特性和高材料吸收性,可以作为直接应用光源。基于条宽为45μm的蓝光芯片,本团队设计了功率大于1000 W的220μm蓝光光纤耦合激光光源:通过空间拼接和偏振合束的方法,将40只芯片耦合进105μm芯径光纤中,再通过7×1泵浦合束技术,最终实现了输出功率为850 W的蓝光半导体激光输出(光纤芯径为220μm,数值孔径为0.22)。这一方案充分利用了光纤的束参积,相当于将280只芯片能量耦合进220μm芯径光纤。通过降额使用、冗余设计、对向光路的优化设计、芯片的老化筛选、降低芯片周围湿度等措施,实现了芯片的平均故障间隔(MTBF)约为1293 h,光纤耦合半导体激光模块的MTBF约为1115 h,为kW级高亮度蓝光光纤耦合光源直接应用激光系统提供了有力支撑。
Objective Blue laser diodes operating at 450 nm can be used as direct application laser sources due to their special wavelength and high material absorption,making them effective for laser welding and printing.Improving the power and brightness of laser diodes(LDs)is a research hotspot.A fiber-coupled blue laser diode with a core diameter of 220μm was designed,with an output power exceeding 1000 W.The chip achieved a mean time between failures(MTBF)of over 1293 h,and the laser module had an MTBF of more than 1115 h.These results can support direct application laser systems based on blue fiber-coupled laser diodes.Methods The 200μm core diameter fiber-coupled LD was achieved using a“(10+10)+(10+10)”multi-step single-chip configuration.Ten single chips were spatially assembled along the fast axis,with 2 channels spatially stacked along the slow axis.Additionally,polarization beam combining of the 2 channels was performed along the slow axis.In total,40 single chips were coupled into a 105μm fiber.To enhance power and brightness,7×1 pumping fiber beam combining technology was utilized to obtain a 220μm fiber-coupled LD.To improve the reliability of the LD module,the operating current was set to 2.4 A,even though the COS(chip on submount)could operate at a maximum current of 3 A.Results and Discussions A blue fiber-coupled laser diode with a 220μm core diameter was successfully developed,achieving a practical output power of 850 W.The module’s reliability was improved through a series of measures including chip derating,redundancy design,optimal design of the opposing optical path,chip burn-in,and reduced humidity in the air surrounding the chip.The electro-optical efficiency of the blue light chips was approximately 38%.After collimation with fast-axis collimators(FAC)and slow-axis collimators(SAC),the efficiency was about 95%.The spatial splicing efficiency(accounting for light blocking and leakage)was approximately 97%,the polarization beam combining efficiency was around 97%,and the fiber coupling efficiency was roughly 97%.Overall,the optical efficiency was approximately 86%,with an overall electro-optical efficiency of about 33%.In addition to using a 7×1 pump combiner for efficient beam combining,a 19×1 pump combiner can also be employed.Using a 55μm fibercoupled LD as the input arm or sub-beam of the fiber combiner,this sub-beam adopts the method of“fast-axis spatial splicing+polarization combining,”stacking 10 single emitters in the fast-axis direction with a step difference of 0.38 mm.The focal lengths of the FAC and SAC are 0.3 mm and 9 mm,respectively,while the aspherical focusing lens has a focal length of 8.5 mm.Conclusions A 105μm fiber-coupled LD module was designed and developed based on a spatial splicing method,with a power exceeding 150 W@NA=0.19.Using 7×1 fiber-pumped beam combining technology,a 220μm fiber-coupled LD was developed,with an output power of 850 W@NA=0.22,which significantly improved the filling ratio and utilization rate of the fiber bundle parameter product.Meanwhile,the reliability of individual chips was enhanced through aging screening,derating,redundant design,optical feedback isolation protection,and reduced ambient humidity.The rated operating current of the chips was reduced from 3 A to 2.4 A,resulting in a chip MTBF of over 1293 h and an 850 W LD module MTBF of more than 1115 h,greatly improving the light source reliability.A series of blue laser effect experiments were conducted using this light source,verifying its practicality.This research provides technical support for the space-based application of a specific laser system and lays a solid foundation for further engineering and practical implementation of high-brightness blue light sources.
作者
张兰平
吴华玲
蒋全伟
郭林辉
王丞乾
高松信
范国滨
Zhang Lanping;Wu Hualing;Jiang Quanwei;Guo Linhui;Wang Chengqian;Gao Songxin;Fan Guobin(Institute of Applied Electronics,China Academy of Engineering Physics(CAEP),Mianyang 621900,Sichuan,China;National Key Laboratory of Science and Technology on Advanced Laser and High Power Microwave,Mianyang 621900,Sichuan,China;Graduate School of Chinese Academy of Engineering Physics(CAEP),Beijing 100088,China;Chinese Academy of Engineering Physics,Mianyang 621900,Sichuan,China)
出处
《中国激光》
2025年第17期10-17,共8页
Chinese Journal of Lasers
基金
中国工程物理研究院军民融合基金项目(2023-JMRH-LG)。
