近日，美国加州大学的John E. Bowers及其研究小组与沙特阿拉伯阿卜杜拉国王科技大学的Yating Wan等人合作并取得一项新进展。经过不懈努力，他们实现在硅上直接生长的量子点激光器的启钥锁定。相关研究成果已于2024年4月26日在国际知名学术期刊《自然—光子学》上发表。

在这项工作中，该研究团队展示了直接在硅上生长的量子点激光器，在启钥外腔锁定下实现了自注入锁定激光相干性。高性能量子点激光器提供了一个可扩展和低成本的异质外延集成平台。此外，得益于量子点激光器的无混沌特性，即使在低质量因子的外腔锁定条件下，洛伦兹线宽也能达到惊人的16Hz。相较于传统的量子阱激光器，其频率噪声更是降低了一个数量级。

据悉，超低噪声激光源对于各种应用至关重要，包括微波合成器、光学陀螺仪和量子系统的操纵。硅光子学已经成为高相干应用的一个有前途的解决方案，因为它能够减少系统的尺寸、重量、功耗和成本。基于自注入锁定的半导体激光器已经实现了光纤激光相干性，但通常需要高质量因子的外腔来通过频率选择反馈抑制相干性坍缩。基于外腔锁定的激光器是一种低成本的启钥操作选择，但其相干性通常不如自注入锁定激光器。

附：英文原文

Title: Turnkey locking of quantum-dot lasers directly grown on Si

Author: Dong, Bozhang, Wan, Yating, Chow, Weng W., Shang, Chen, Prokoshin, Artem, Alkhazraji, Emad, Koscica, Rosalyn, Wang, Heming, Bowers, John E.

Issue&Volume: 2024-04-26

Abstract: Ultralow-noise laser sources are crucial for a variety of applications, including microwave synthesizers, optical gyroscopes and the manipulation of quantum systems. Silicon photonics has emerged as a promising solution for high-coherence applications due to its ability to reduce the system size, weight, power consumption and cost. Semiconductor lasers based on self-injection locking have achieved fibre laser coherence, but typically require a high-quality-factor external cavity to suppress coherence collapse through frequency-selective feedback. Lasers based on external-cavity locking are a low-cost and turnkey operation option, but their coherence is generally inferior to self-injection locking lasers. In this work, we demonstrate quantum-dot lasers grown directly on Si that achieve self-injection-locking laser coherence under turnkey external-cavity locking. The high-performance quantum-dot laser offers a scalable and low-cost heteroepitaxial integration platform. Moreover, the chaos-free nature of the quantum-dot laser enables a 16Hz Lorentzian linewidth under external-cavity locking using a low-quality-factor external cavity, and improves the frequency noise by an additional order of magnitude compared with conventional quantum-well lasers.

DOI: 10.1038/s41566-024-01413-2

Source: https://www.nature.com/articles/s41566-024-01413-2