波导结构对905 nm隧道结级联半导体激光器的光束质量和功率的影响

Effect of waveguide structure on beam quality and power of 905 nm cascade semiconductor lasers with tunnel junctions

  • 摘要: 近年来,激光雷达应用对探测距离和灵敏度提出了更高的要求。905 nm半导体激光器作为其理想光源也亟待提升峰值功率与光束质量。在这个背景下,基于非对称大光腔结构研究了不同增益区类型和波导结构对905 nm隧道结脉冲半导体激光器的光束质量和功率效率的影响。通过优化增益区类型和波导结构降低了体电阻和内损耗;增强了限制载流子泄露的能力,提高了器件在高电流下工作的峰值功率和电光效率;通过提高高阶模对基模的阈值增益比值,抑制高阶模式激射,降低了远场发散角。在此基础上,研制的800 μm腔长、200 μm条宽的四有源区半导体激光器在100 ns脉冲宽度、1 kHz重复频率的脉冲功率测试中,41.6 A的脉冲电流强度下实现了峰值功率输出177 W;垂直于PN结方向单模激射,远场发散角半高全宽为24.3°。

     

    Abstract: In recent years, lidar applications had put forward higher requirements for detection distance and sensitivity. As an ideal light source, 905 nm semiconductor lasers also urgently needed to improve the peak power and beam quality. In this context, the effects of different gain region types and waveguide structures on beam quality and power efficiency of 905 nm tunnel-junction pulsed semiconductor lasers were investigated based on asymmetric large optical cavity structures. By optimizing the gain region type and waveguide structure, the bulk resistance and internal loss were reduced. The ability to limit carrier leakage was enhanced, and the peak power and electro-optical efficiency of the device working at high currents were improved. By increasing the threshold gain ratio of the multimode to the fundamental mode, the high-order mode lasing was suppressed, and the far-field divergence angle was reduced. On this basis, the developed quadruple-active regions semiconductor laser with 800 μm cavity length and 200 μm electrode achieved a peak power output of 177 W at a pulse current intensity of 41.6 A in pulse power test with a pulse width of 100 ns and a repetition rate of 1 kHz; fundamental mode emitting in the vertical direction, the full width at half maximμm far-field divergence angle was 24.3°.

     

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