Self-stabilization mechanism in ultra-stable Fourier domain mode-locked (FDML) lasers
Self-stabilization mechanism in ultra-stable Fourier domain mode-locked (FDML) lasers
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DOI：
10.1364/osac.389972
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发表时间：
2020-02
期刊：
影响因子：
1.6
通讯作者：
M. Schmidt;T. Pfeiffer;C. Grill;R. Huber;C. Jirauschek
中科院分区：
文献类型：
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作者：
M. Schmidt;T. Pfeiffer;C. Grill;R. Huber;C. Jirauschek
了解傅里叶域锁模（FDML）激光器的动力学特性对于确定物理相干极限和寻找新的上级实验实现方法至关重要。此外，在激光环系统中的线性和非线性效应的丰富的相互作用是非常重要的理论兴趣。在这里，我们研究了一个高度色散补偿的设置，在超过100 nm的带宽，一个高度相干的输出与近散粒噪声限制强度波动的动态实验证明。这个输出称为最佳点。我们通过数值模拟表明，在FDML激光器的光纤延迟腔中的有限量的剩余色散可以补偿的群延迟色散的扫频带通滤波器，使强度迹线表现出没有下降或高频失真，这是在激光器中的主要噪声源。以相同的方式，可以容忍与理想扫描滤波器频率的小失谐。此外，我们发现滤波器的群延迟色散改善了激光器的相干特性，并在腔中充当自稳定元件。我们的理论模型进行了验证，对实验数据，表明所有相关的物理效应的甜蜜点操作制度。
Understanding the dynamics of Fourier domain mode-locked (FDML) lasers is crucial for determining physical coherence limits, and for finding new superior methods for experimental realization. In addition, the rich interplay of linear and nonlinear effects in a laser ring system is of great theoretical interest. Here we investigate the dynamics of a highly dispersion-compensated setup, where over a bandwidth of more than 100 nm, a highly coherent output with nearly shot-noise-limited intensity fluctuations was experimentally demonstrated. This output is called the sweet-spot. We show by numerical simulation that a finite amount of residual dispersion in the fiber delay cavity of FDML lasers can be compensated by the group delay dispersion in the swept bandpass filter, such that the intensity trace exhibits no dips or high-frequency distortions, which are the main source of noise in the laser. In the same way, a small detuning from the ideal sweep filter frequency can be tolerated. Furthermore, we find that the filter's group delay dispersion improves the coherence properties of the laser, and acts as a self-stabilizing element in the cavity. Our theoretical model is validated against experimental data, showing that all relevant physical effects for the sweet-spot operating regime are included.