Gain Compression and Above-Threshold Linewidth Enhancement Factor in 1.3-μm InAs-GaAs Quantum-Dot Lasers
Gain Compression and Above-Threshold Linewidth Enhancement Factor in 1.3-μm InAs-GaAs Quantum-Dot Lasers
复制标题
DOI：
10.1109/jqe.2008.2003106
复制
发表时间：
2008-09-01
影响因子：
2.5
通讯作者：
Lester, Luke F.
中科院分区：
文献类型：
--
作者：
Grillot, Frederic;Dagens, Beatrice;Lester, Luke F.
量子点（QD）激光器具有低阈值电流、温度和反馈不敏感性、无啁啾行为和低线宽增强因子（α（H）因子）等许多有用的特性。虽然已经证明了许多突破，但最大调制带宽在QD器件中仍然有限，并且通常观察到调制响应的强阻尼，指出增益压缩的作用。本文研究了1.3 μ mInAs-GaAs量子点激光器中增益压缩的影响及其对阈上α（H）因子的影响。一个模型被用来解释的α（H）因子与注入电流的依赖关系，并与AM/FM实验进行了比较。最后，示出了最大增益越高，增益压缩的效果越低，并且α（H）因子越低。该分析可用于设计具有改进的调制带宽的无啁啾QD激光器以及在直接调制下的无隔离器传输。
Quantum-dot (QD) lasers exhibit many useful properties such as low threshold current, temperature and feedback insensitivity, chirpless behavior, and low linewidth enhancement factor (alpha(H)-factor). Although many breakthroughs have been demonstrated, the maximum modulation bandwidth remains limited in QD devices, and a strong damping of the modulation response is usually observed pointing out the role of gain compression. This paper investigates the influence of the gain compression in a 1.3-mu m InAs-GaAs QD laser and its consequences on the above-threshold alpha(H)-factor. A model is used to explain the dependence of the alpha(H)-factor with the injected current and is compared with AM/FM experiments. Finally, it is shown that the higher the maximum gain, the lower the effects of gain compression and the lower the alpha(H)-factor. This analysis can be useful for designing chirpless QD lasers with improved modulation bandwidth as well as for isolator-free transmission under direct modulation.