This work presents a rate equation model for interband cascade lasers, which is used for investigating modulation dynamics and optical noise properties. Through standard small-signal analysis of the rate equations, we analytically derive the resonance frequency, the damping factor, the relative intensity noise (RIN), and the frequency noise (FN) of the interband cascade lasers. It is shown that more cascading stages are beneficial for reaching a broad modulation bandwidth at a low pump current. On the other hand, fewer cascading stages are favorable to achieve low-RIN and low-FN (or narrow-linewidth) laser emission.

中文翻译：

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带间级联激光器调制和噪声动力学的速率方程建模

这项工作提出了带间级联激光器的速率方程模型，用于研究调制动力学和光噪声特性。通过速率方程的标准小信号分析，我们分析导出了带间级联激光器的谐振频率、阻尼因子、相对强度噪声（RIN）和频率噪声（FN）。结果表明，更多级联级有利于在低泵浦电流下达到宽调制带宽。另一方面，较少的级联级有利于实现低 RIN 和低 FN（或窄线宽）激光发射。