提出了一种高电光转换效率的新型复合波导半导体激光器结构(Composite Waveguide LD, CWG LD)。该器件结构高的电光转换效率得益于其所采用的Al组分阶梯分布AlxGa1-xAs波导层。通过优化设计波导层电阻率分布及能带分布, CWG LD结构在保证输出光功率的同时, 可以有效地降低器件串联电阻并提高电光转换效率。结合理论分析及计算机数值仿真软件, 分析了复合波导提升器件电光转换效率的机理。经优化, 在激光器条宽为6 μm、腔长为1 000 μm的情况下, 波导层阶梯数为1时CWG LD结构可以获得最大的电光转换效率。研究结果表明: 在注入电流为900 mA时, CWG LD结构的串联电阻由常规波导器件结构的3.51 Ω降低为2.67 Ω, 电光转换效率由54.7%提升至69.5%。

A novel structure of high electro-optic conversion efficiency semiconductor laser with composite waveguide was presented. Because of the AlxGa1-xAs waveguide layer with Al component step distribution, the electro-optic conversion efficiency of the device was high. Due to the optimal design of distribution of resistivity and band, the series resistance of the semiconductor laser was reduced while resulting in the improvement of electro-optic conversion efficiency without reducing the optical power. Based on the theoretical analysis and software simulation, the mechanism of the electro-optic conversion efficiency of the composite waveguide was analyzed. In the condition that the laser width was 6 μm and the cavity length was about 1 000 μm, the material composition distribution was optimized, and a step of the composite waveguide laser could achieve maximum electro-optical conversion efficiency. The results show that the series resistance of the semiconductor laser with composite waveguide is reduced from 3.51 Ω of the conventional laser structure with conventional waveguide to 2.67 Ω, and the electro-optic conversion efficiency is increased from 54.7% to 69.5% at 900 mA.