Cuyvers Stijn, Poelman Stijn, Van Gasse Kasper, Kuyken Bart
Photonics Research Group, INTEC Department, Ghent University - imec, 9052, Ghent, Belgium.
Center for Nano- and Biophotonics, Ghent University, Ghent, Belgium.
Sci Rep. 2021 May 11;11(1):10027. doi: 10.1038/s41598-021-89508-6.
Semiconductor-based mode-locked lasers, integrated sources enabling the generation of coherent ultra-short optical pulses, are important for a wide range of applications, including datacom, optical ranging and spectroscopy. As their performance remains largely unpredictable due to the lack of commercial design tools and the poorly understood mode-locking dynamics, significant research has focused on their modeling. In recent years, traveling-wave models have been favored because they can efficiently incorporate the rich semiconductor physics of the laser. However, thus far such models struggle to include nonlinear and dispersive effects of an extended passive laser cavity, which can play an important role for the temporal and spectral pulse evolution and stability. To overcome these challenges, we developed a hybrid modeling strategy by unifying the traveling-wave modeling technique for the semiconductor laser sections with a split-step Fourier method for the extended passive laser cavity. This paper presents the hybrid modeling concept and exemplifies for the first time the significance of the third order nonlinearity and dispersion of the extended cavity for a 2.6 GHz III-V-on-Silicon mode-locked laser. This modeling approach allows to include a wide range of physical phenomena with low computational complexity, enabling the exploration of novel operating regimes such as chip-scale soliton mode-locking.
基于半导体的锁模激光器是一种能够产生相干超短光脉冲的集成光源，在包括数据通信、光学测距和光谱学在内的广泛应用中都非常重要。由于缺乏商业设计工具以及对锁模动力学的理解不足，其性能在很大程度上仍然不可预测，因此大量研究都集中在对它们的建模上。近年来，行波模型受到青睐，因为它们可以有效地纳入激光器丰富的半导体物理特性。然而，到目前为止，此类模型难以纳入扩展无源激光腔的非线性和色散效应，而这些效应对于脉冲的时间和光谱演化及稳定性可能起着重要作用。为了克服这些挑战，我们通过将半导体激光部分的行波建模技术与扩展无源激光腔的分步傅里叶方法相结合，开发了一种混合建模策略。本文介绍了这种混合建模概念，并首次例证了扩展腔的三阶非线性和色散对于2.6吉赫兹硅基III-V族锁模激光器的重要性。这种建模方法能够以低计算复杂度纳入广泛的物理现象，从而能够探索诸如芯片级孤子锁模等新型工作模式。
