We present experiments and numerical simulations of optical frequency combs generated by gain-switching a single mode laser diode when subject to optical injection. Our analysis focuses on the combs with a frequency separation $f_R$ in the GHz range. We present experimental maps in the parameter space spanned by the detuning and the strength of the optical injection that identify the boundaries between regions with different dynamical states. A rich variety of nonlinear behaviors including injection-locked, unlocked and irregular combs are observed and analyzed. The dynamical state corresponding to an injection locked comb, P$N$, is characterized by an optical phase oscillation with a well defined amplitude in such a way that repeats or changes in 2$\pi$ with an $N/f_R$ period, where $N$ is a natural number. Different regions of locked combs with a tongue shape around detuning values given by multiples of $f_R$ appear in the maps. P1 and P2 are the most widespread locked states for large values of the modulation amplitude. As this amplitude decreases a much larger variety of P$N$ states with large values of $N$ appear in small area regions of the map. Our numerical simulations are in very good agreement with experimental results.

中文翻译：

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由激光二极管增益切换产生的光频梳中的光注入引起的非线性动力学

我们展示了在受到光注入时通过增益切换单模激光二极管产生的光频率梳的实验和数值模拟。我们的分析侧重于频率分离的梳子$f_R$在 GHz 范围内。我们在由失谐和光学注入强度跨越的参数空间中呈现实验图，用于识别具有不同动力学状态的区域之间的边界。观察和分析了多种非线性行为，包括注入锁定、解锁和不规则梳状。对应于注入锁定梳的动态状态，P$N$，其特征在于具有明确定义的振幅的光学相位振荡，其重复或变化为 2$\pi$ 与 $N/f_R$ 期间，其中 $N$是一个自然数。锁定梳的不同区域具有舌形围绕由多个给定的失谐值$f_R$出现在地图中。对于较大的调制幅度值，P1 和 P2 是最普遍的锁定状态。随着这个幅度的降低，P 的变化更大$N$ 具有大值的状态 $N$出现在地图的小区域区域。我们的数值模拟与实验结果非常吻合。