Wan Zhengyi, Cen Qizhuang, Xu Kun, Li Ming, Dai Yitang
Opt Express. 2025 Jun 30;33(13):27668-27677. doi: 10.1364/OE.563993.
Integrated electro-optic (EO) frequency combs are pivotal components in a wide range of applications, including optical communications, spectroscopy, optical computing, precision timing, and frequency measurement. Although broadband on-chip EO combs are typically generated within resonators possessing high-quality factors, their relatively low conversion efficiency remains a significant constraint. By comparison, EO combs produced in dual rings exhibit enhanced conversion efficiencies, which generally necessitate satisfying a generalized critical coupling condition. In this work, we employ a virtual state model to successfully derive a generalized critical coupling condition for dual-ring modulators under detuning modulation. Based on this theory, we obtain an approximate analytical solution for the dual-ring detuning modulation, showing that it can be equated to phase modulation. In addition, this condition provides a direct guide for selecting modulation parameters of the dual ring, leading to more precise control and optimization. Utilizing this condition, we have designed an efficient and energy-concentrated EO comb generation system that permits a wide range of possibilities in the choice of driving frequency and modulation depth. Our theoretical approach provides an optimization strategy for efficient EO comb generation, offering more compact, high-performance, and flexible solutions for high-speed data transmission, sensing, and quantum optical computing systems.
集成电光（EO）频率梳是包括光通信、光谱学、光计算、精密计时和频率测量在内的广泛应用中的关键组件。尽管宽带片上EO频率梳通常在具有高品质因数的谐振器内产生，但其相对较低的转换效率仍然是一个重大限制。相比之下，双环中产生的EO频率梳具有更高的转换效率，这通常需要满足广义临界耦合条件。在这项工作中，我们采用虚态模型成功推导出了失谐调制下双环调制器的广义临界耦合条件。基于该理论，我们得到了双环失谐调制的近似解析解，表明它可以等同于相位调制。此外，该条件为双环调制参数的选择提供了直接指导，从而实现更精确的控制和优化。利用这一条件，我们设计了一种高效且能量集中的EO频率梳产生系统，该系统在驱动频率和调制深度的选择上具有广泛的可能性。我们的理论方法为高效EO频率梳产生提供了一种优化策略，为高速数据传输、传感和量子光计算系统提供了更紧凑、高性能和灵活的解决方案。
