一种具有自适应自线性化的鲁棒赫兹线宽量子点相干扫频源
A Robust Hertz-Linewidth Quantum-Dot Coherent Swept Source with Adaptive Self-Linearization
- State Key Laboratory for Extreme Photonics and Instrumentation, Zhejiang Key Laboratory of Optoelectronic Information Technology, College of Optical Science and Engineering, International Research Center for Advanced Photonics, Zhejiang University（浙江大学）
- State Key Laboratory of Optoelectronic Materials and Technologies, School of Electronics and Information Technology, Sun Yat-Sen University（中山大学）
- China Jiliang University（中国计量大学）
- Intelligent Optics and Photonics Research Center, Jiaxing Research Institute, Zhejiang University（浙江大学嘉兴研究院）
机构由 AI 辅助整理，请以论文原文为准。
AI总结：
本文提出一种量子点相干扫频源，通过源物理与系统控制协同设计，实现12.6 Hz线宽和23.2 GHz啁啾带宽，并借助迭代学习控制将非线性降至极低，为光学测距和微波雷达提供统一FMCW平台。
AI中文摘要：
调频连续波（FMCW）技术支撑着相干光学测距和微波雷达，在光学和微波领域共同产生了对高相干性和高线性频率啁啾源的普遍需求。然而，传统半导体激光器从根本上受到线宽、线性可调性和操作鲁棒性之间权衡的限制。在此，我们通过源物理和系统控制的协同设计，提出了一种鲁棒的自线性化量子点（QD）相干扫频源架构。量子点激光器的无混沌特性使得稳定的低品质因数外腔锁定成为可能，从而获得12.6 Hz的洛伦兹线宽。与自注入锁定激光器不同，宽带外部光学反馈允许激光器在宽电流调谐范围内保持高光学相干性和稳定运行，从而在23.2 GHz的啁啾带宽下实现鲁棒的免按键操作。此外，一种统计门控的实时迭代学习控制（ILC）策略将啁啾非线性度$(1-R^2)$降低至低达$8.96\ imes10^{-8}$，同时在激光器温度变化下保持优异的环境稳定性。为展示实用性，我们演示了无隔离器相干激光雷达和频率捷变、线性啁啾微波波形的光子产生，为光学测距和雷达波形合成建立了一个通用的FMCW源平台。据我们所知，我们首次展示了一种基于量子点的相干扫频源，它同时结合了赫兹级线宽和超高啁啾线性度，我们设想它作为FMCW信号生成和跨光学与微波领域相干传感的统一源平台。
英文摘要：
Frequency-modulated continuous-wave (FMCW) techniques underpin both coherent optical ranging and microwave radar, creating a common demand for highly coherent and highly linear frequency-chirped sources across the optical and microwave domains. Conventional semiconductor lasers, however, are fundamentally constrained by trade-offs among linewidth, linear tunability, and operational robustness. Here, we present a robust self-linearized quantum-dot (QD) coherent swept-source architecture through the co-design of source physics and system control. The chaos-free characteristics of QD lasers enable stable low-quality-factor external-cavity locking, yielding a Lorentzian linewidth of 12.6 Hz. Unlike self-injection-locked lasers, broadband external optical feedback allows the laser to maintain high optical coherence and stable operation over a wide current-tuning range, thereby enabling robust turnkey operation together with a chirp bandwidth of 23.2 GHz. Furthermore, a statistically gated real-time iterative learning control (ILC) strategy reduces the chirp nonlinearity $(1-R^2)$ to as low as $8.96\times10^{-8}$, while maintaining excellent environmental stability under laser-temperature variations. To demonstrate practicality, we demonstrate isolator-free coherent LiDAR and photonic generation of frequency-agile, linearly chirped microwave waveforms, establishing a common FMCW source platform for optical ranging and radar waveform synthesis. To the best of our knowledge, we demonstrate for the first time a QD-based coherent swept source that simultaneously combines hertz-level linewidth and ultrahigh chirp linearity, which we envision as a unified source platform for FMCW signal generation and coherent sensing across the optical and microwave domains.
