为了提高980 nm半导体激光器的输出功率并获得较小的远场发散角,在非对称波导结构的基础上设计了n型波导结构,即在n型波导中引入高折射率的内波导层。采用理论计算和SimLastip软件模拟对常规非对称波导结构和内波导结构进行了研究。利用分子束外延系统生长980 nm内波导结构的外延材料, 并制作了激光器。对于条宽为100 μm、腔长为1000 μm的器件,阈值电流为97 mA,斜率效率为1.01 W/A；当注入电流为500 mA时,远场发散角为29°(垂直向) × 8°(水平向),与模拟结果相符。理论计算和实验结果表明：较之于常规非对称波导结构,内波导结构可有效降低光场限制因子,提高输出功率,减小远场发散角。

In order to raise the output power and lower the far field divergence angles of 980 nm diode laser, a high refractive index inner waveguide is introduced in the n-type waveguide structure, which is based on the asymmetric waveguide structure. The research is conducted by SimLastip. Meanwhile, the semiconductor laser is fabricated with the epitaxial layer grown by a solid source molecular beam epitaxy (MBE) system. The fabricated 980 nm laser diode with 100 μm strip width and 1000 μm cavity length has a threshold current of 97 mA and a slope efficiency of 1.01 W/A. When the injection current is 500 mA, the far field divergence angles are 29°(vertical) by 8° (horizontal), which is consistent with the simulated result. The theoretical and experimental results indicate that the inner waveguide structure can achieve high power output, effectively reduce the far field divergence angle and improve the beam quality of the device.