Hybrid Chip-Scale Frequency Combs Combining III-V Quantum-Dash Mode-Locked Lasers and High-Q Silicon-Nitride Microresonators

芯片规模的光学频率梳发生器有可能给科学和工业中的许多应用带来革命性的变化，包括使用大规模并行波分复用(WDM)的高吞吐量光通信、超高速光学测距和LiDAR，以及超宽带光电信号处理。然而，尽管实验室实验已经显示了这种方案的非凡潜力，但在实际应用中的实际可行性仍然受到目前可用的梳状源的根本缺陷的限制。具体地说，目前还没有梳状发生器的概念，可以提供具有低光学线宽和相位噪声的宽带平滑频谱，同时在芯片级封装中提供简单和省电的操作。Hybridge Combs旨在通过探索、设计、实现和实验演示一种新型的芯片级频率梳源来克服这一不足，这种新型频率梳源结合了孤子克尔梳子和基于低维III-V化合物的锁模激光器的独特优势。在技术层面，我们的方法依赖于混合多芯片模块，该模块将量子短划线锁模激光二极管(QD-MLLD)或基于QD的反射半导体光放大器(QD-RSOA)与专门联合设计的线性和非线性氮化硅(SiN)基光子电路相结合，从而融合了两个集成平台的互补优势。在该项目中，我们将建立一个详细的理论框架，通过光学线性和非线性氮化硅反馈电路来定量描述QD-MLLD或QD-RSOA的多色调注入锁定，设计并实现底层的III-V和SIN器件，并通过先进的3D打印光学耦合元件将它们结合在一起。在此基础上，我们将实现在线宽和功耗方面具有前所未有的性能参数的混合芯片级梳状光源，并在实验上展示其在大规模并行光通信、高精度光学测距或超宽带光电信号处理等特定应用中的实用可行性。该项目联盟由来自法国和德国的国际领先团队组成，他们处于完美的地位，可以在国际科学前沿解决拟议中的研究。我们预计，设想的梳状源的成功展示将对一系列工业和科学应用产生变革性影响，该联盟内的合作伙伴可以有效地处理这些应用。

Chip-scale optical frequency comb generators have the potential to revolutionize many applications in science and industry, comprising high-throughput optical communications using massively parallel wavelength-division multiplexing (WDM), ultra-fast optical ranging and LiDAR, as well as ultrabroadband photonic-electronic signal processing. However, while laboratory experiments have shown the extraordinary potential of such schemes, the practical viability in real applications is still limited by fundamental deficiencies of currently available comb sources. Specifically, there is at present no comb generator concept that can provide broadband smooth spectra with low optical linewidth and phase noise, while offering simple and power-efficient operation in a chip-scale package. HybridCombs aims at overcoming this lack by exploring, designing, implementing, and experimentally demonstrating a novel class of chip-scale frequency comb sources, that combine the distinct advantages of soliton Kerr combs with those of mode-locked lasers based on low-dimensional III-V compounds. On a technological level, our approach relies on hybrid multi-chip modules that combine quantum-dash mode-locked laser diodes (QD-MLLD) or QD-based reflective semiconductor optical amplifiers (QD-RSOA) with specifically co-designed linear and nonlinear silicon-nitride-(SiN-)based photonic circuits, thereby merging the complementary strengths of the two integration platforms. Within the project, we shall establish a detailed theoretical framework that allows to quantitatively describe multi-tone injection locking of QD-MLLD or QD-RSOA by optically linear and nonlinear silicon-nitride feedback circuits, design and realize the underlying III-V and SiN devices, and combine them by means of advanced 3D-printed optical coupling elements. Based on these foundations, we will realize hybrid chip-scale comb sources with unprecedented performance parameters in terms of linewidth and power consumption and experimentally demonstrate their practical viability in selected applications such as massively parallel optical communications, high-precision optical ranging, or ultra-broadband photonic-electronic signal processing. The project consortium consists of internationally leading teams from France and Germany, that are in a perfect position to tackle the proposed research at the international forefront of science. We expect that successful demonstration of the envisaged comb sources will be of transformative impact to a series of industrial and scientific applications that can be efficiently addressed by the partners within the consortium.