基于楔形微透镜补偿半导体激光阵列指向偏差

Compensation of directivity deviation of laser diode based on the wedge-shaped microlens-array

针对半导体激光阵列的发光单元指向性偏差导致快轴光束质量显著劣化的现象,研究了发光单元指向性偏差对快轴光束质量的影响,提出了一种利用微光学元件补偿发光单元指向性偏差的方法,设计了一种楔形微透镜阵列,可实现单个bar条的光束耦合进芯径200μm、NA=0.2的光纤。模拟计算结果表明,楔形微透镜阵列的补偿作用可使半导体激光阵列快轴方向的光参数积由64.24 mm·mrad下降到58.14 mm·mrad,光纤耦合效率达到95.6%,相比补偿前提高了10.4%。为降低工艺难度,采用分类补偿的方法,模拟光纤耦合效率达到91.5%。考虑到工业应用,采用由三片楔形透镜组成的透镜组对分类后的发光单元光束分别进行补偿,测量得到的光纤耦合效率为90.4%,比补偿光束指向性之前的耦合效率提高了约7%。

Aiming at the phenomenon that the beam quality of laser diode array could be deteriorated by the directivity deviation of emitters in the fast axis obviously,the influence of directivity deviation of emitters on beam quality in fast axis is studied.A method that the micro-optic allows for the compensation of directivity deviation is put forward and the wedge-shaped microlens-array is designed.As a result,the laser beams of a single bar are coupled into a standard fiber with 200μm core diameter and 0.2 numerical apertures(NA).The simulation results show that the beam parameters product of laser diode array is decreased from 64.24 mm·mrad to 58.14 mm·mrad in the fast axis,and the fiber coupling efficiency is up to 95.6%,which is improved by 10.4%.In order to reduce the process difficulty,the fiber coupling efficiency reaches 91.5%by using the classification compensation method.Considering the industrial application,the wedge lens group composed of three wedge-shaped lenses is applied to compensate the beam directivity of the classified emitters respectively.The measured optical fiber coupling efficiency is 90.4%,which is improved by 7%.