Ulanov Alexander E, Wildi Thibault, Bhatnagar Utkarsh, Herr Tobias
Opt Lett. 2024 Nov 1;49(21):6261-6264. doi: 10.1364/OL.539725.
Self-injection locking (SIL) of laser diodes to microresonators is a powerful technique that enables compact narrow-linewidth lasers. Here, we extend this technique to chip-integrated Fabry-Perot (FP) microresonators, which offer high-quality factors and large mode volumes in a compact footprint, reducing fundamental thermorefractive noise (TRN). The resonators consist of a silicon nitride waveguide terminated by two photonic crystal reflectors fabricated via scalable ultraviolet lithography. Evanescent side-coupling allows precise tuning of the SIL feedback mechanism. We present a theoretical model and experimentally demonstrate SIL, resulting in a fundamental thermorefractive-noise-limited laser. The experiments and the theoretical model are in excellent agreement. These results complement current SIL techniques and are relevant to chip-scale low-noise laser systems.
激光二极管自注入锁定（SIL）到微谐振器是一种强大的技术，可实现紧凑型窄线宽激光器。在此，我们将该技术扩展到芯片集成的法布里-珀罗（FP）微谐振器，这种微谐振器在紧凑的尺寸内提供高品质因数和大模式体积，降低了基本热折射噪声（TRN）。这些谐振器由一个氮化硅波导组成，该波导由通过可扩展紫外光刻制造的两个光子晶体反射器终止。倏逝侧耦合允许对SIL反馈机制进行精确调谐。我们提出了一个理论模型，并通过实验证明了SIL，从而得到了一个基本热折射噪声限制的激光器。实验与理论模型吻合得非常好。这些结果补充了当前的SIL技术，并且与芯片级低噪声激光系统相关。
