利用2只915 nm半导体激光短列阵作为子模块,设计并研制出连续输出的高亮度光纤耦合模块。首先对每个半导体激光短列阵进行光束整形,从而提高它的光束质量;然后采用空间复用技术将这两个半导体激光短列阵出射的激光在光参数积小的方向上叠加,并利用偏振复用技术进一步提高光束质量;最后利用单片非球面透镜将激光聚焦到芯径为100μm、数值孔径为0.22的光纤中。测量结果显示:在工作电流为52.5A时,聚焦镜焦平面的光斑尺寸为105.4μm;耦合后测量光纤出光功率可达72.6 W,对应亮度为6.08 MW/(cm2.sr),模块的电光转换效率为42.2%。最后测量了模块在不同驱动电流时的光谱,证明该模块的散热性能良好。
Two 915 nm diode laser short bars were used as sub-module to manufacture high brightness fiber coupled module with continuous wave(CW) output power.Firstly,beam shaping technology was employed for each sub-module to enhance its beam quality.Secondly,the two beams were stacked in direction of lower beam parameter product by means of spatial multiplexing technology.Finally,the laser was focusing into a multimode fiber with 200 μm core diameter and NA=0.22 by optimized lens by focusing lens.Experiment results show that the beam waist diameter at focal plane is 105.4 μm when driving current is 52.5 A,the optical power output from fiber can reach to 72.6 W with a brightness of 6.08 MW/(cm2·sr),and the wallplug efficiency is 42.2% when driving current is 52.5 A.The character of heat dissipation was studied by means of measuring spectrum with different current,and the results prove that the module has favorable heat dissipation.