高功率垂直腔面发射半导体激光器优化设计研究

Optimal designs for high-power vertical cavity surface emitting lasers

与传统的端发射半导体激光器相比 ,垂直腔面发射半导体激光器 (VCSEL)具有可单模输出 ,光束对称性好 ,可被高度聚焦 ,进入光纤的耦合效率极高和有利于大规模二维列阵等优点 .为了得到高功率的激光输出 ,除了要增大VCSEL的发射面积之外 ,关键的是要选择适当的量子阱层数、有源区电流密度的均匀分布和良好的热管理等 .本文详细研究和分析了高功率VCSEL有源区量子阱层数 ,有源区直径 ,材料的热导和电阻 ,电极间距等对VCSEL器件性能的影响 .通过优化参数 ,进行最佳设计 ,研制出了 980nmIn0 .2 Ga0 .8As GaAsVCSEL器件 ,单管室温连续波输出功率已达 1 .95W 。

Vertical cavity surface emitting lasers (VCSEL's) lase in a single longitudinal mode, have a circularly symmetric output beam that can be very tightly focused, offer extremely high coupling efficiencies into optical fiber, and can be mass produced in two-dimensional arrays relative to the conventional edge_emitting semiconductor laser. To obtain a high optical output power, besides enlarging of VCSEL's lasing area, the key points are proper number of quantum wells, homogeneous distribution of current density in the active layer and good thermal control. The dependence of VCSEL's performance on the number of quantum wells, the active diameter, the thermal conductivity and the electric resistance of the material; and the distance between electrical contacts are investigated. By optimizing the design parameters for a 980 nm In 0 2 Ga 0 8 As/GaAs VCSEL, a maximum continuous wave (cw) output power of 1.95 W at room temperature is obtained, which to our knowledge is the highest cw output power of any single VCSEL so far.