Title: Effective Rabi frequency in semiconductor lasers and the origin of self-starting harmonic frequency combs Show Chinese title

Title: 半导体激光器中的有效拉比频率与谐波频率梳自启动的起源

Abstract: Optical frequency combs have become a key research topic in optics and photonics. A peculiar comb state is the harmonic frequency comb (HFC), where optical lines are spaced by integer multiples of the cavity's free-spectral range. The spontaneous formation of HFCs has recently been observed in semiconductor lasers with fast gain recovery, such as Quantum Cascade Lasers (QCLs), although the underlying physical mechanism remains unclear. In this work, we provide a physical interpretation for the formation of HFCs in QCLs, based on a resonance phenomenon between an effective Rabi frequency and a mode of the laser cavity. This is corroborated by the results of the numerical integration of the effective semiconductor Maxwell-Bloch equations used to describe the multimode laser dynamics, as well as by the linear stability analysis of the continuous wave emission at threshold. Show Chinese abstract

Abstract: 光学频率梳已成为光学和光子学领域的一个关键研究课题。 一种特殊的梳状状态是谐波频率梳（HFC），其中光谱线间隔为腔体自由光谱范围的整数倍。 最近，在具有快速增益恢复的半导体激光器中观察到了HFC的自发形成，例如量子级联激光器（QCL），尽管其背后的物理机制仍不清楚。 在这项工作中，我们基于有效拉比频率与激光腔模式之间的共振现象，为QCL中HFC的形成提供了物理解释。 通过有效半导体Maxwell-Bloch方程的数值积分结果以及阈值连续波发射的线性稳定性分析，证实了这一解释。