百瓦级高亮度光纤耦合半导体激光模块的研制

用3只976 nm半导体激光短列阵作为子模块,研制出连续工作的百瓦级高亮度光纤耦合模块。首先,利用光束转换器将每个半导体激光短列阵进行光束整形;然后采用空间复用技术将3个半导体激光短列阵在光参数积小的方向上叠加,并利用倒置伽利略望远镜作为扩束器进一步压缩发散角;最后利用优化结构的透镜组将激光聚焦到芯径200 μm,数值孔径为0.22的光纤中。测量结果显示:聚焦后激光的发散角为24.8°,焦平面的光斑尺寸为175.2 μm;耦合后测量光纤出光功率可达107 W,对应亮度为2.23 MW/(cm²·sr),达到了国内利用列阵进行光纤耦合的领先水平;在工作电流为52.5 A时,电光转换效率为43.1%,远高于全固态等激光器;最后测量本模块在不同驱动电流时的光谱,并以此计算出模块的热阻为1.29 K/W,说明它的散热性能良好。结果表明,本光纤耦合模块适合应用于泵浦光纤激光器、医疗和激光加工等领域。

Reaearch on High Brightness Fiber Coupled Diode Laser Module with Hundred Watts Class Output Power

Three 976 nm diode laser short bars were used as submodule to manufacture high brightness fiber coupled module with CW hundred watts class output power.First,beam transform systems were employed to shape beams emitted from each submodlue;Second,the three beams were stacked in direction of lower beam parameter product by means of spatial multiplexing technology;Finally,the laser was focused into a multimode fiber with 200 μm core diameter and NA=0.22 by optimized lens.Experiment result showed that divergence angle of the focused laser beam was 24.8° and its beam waist diameter was 175.2 μm;laser output from fiber could reach to 107 W,equalizing brightness of 2.23 MW/(cm2·sr),which is a higher level in China.Furthermore,the wall plug efficiency is 43.1% when driving current is 52.5 A,which is far higher than that of solid state laser.Finally the thermal resistance was computed by means of measuring spectrum with different current and the result is 1.29 K/W which indicates favorable heat dissipation of the module.All of the result showed that the module can be used in the field of pumping fiber lasers,medical,material processing and so on.