Guo Joel, McLemore Charles A, Xiang Chao, Lee Dahyeon, Wu Lue, Jin Warren, Kelleher Megan, Jin Naijun, Mason David, Chang Lin, Feshali Avi, Paniccia Mario, Rakich Peter T, Vahala Kerry J, Diddams Scott A, Quinlan Franklyn, Bowers John E
Department of Electrical and Computer Engineering, University of California, Santa Barbara, Santa Barbara, CA 93106, USA.
National Institute of Standards and Technology, 325 Broadway, Boulder, CO 80305, USA.
Sci Adv. 2022 Oct 28;8(43):eabp9006. doi: 10.1126/sciadv.abp9006.
Lasers with hertz linewidths at time scales of seconds are critical for metrology, timekeeping, and manipulation of quantum systems. Such frequency stability relies on bulk-optic lasers and reference cavities, where increased size is leveraged to reduce noise but with the trade-off of cost, hand assembly, and limited applications. Alternatively, planar waveguide-based lasers enjoy complementary metal-oxide semiconductor scalability yet are fundamentally limited from achieving hertz linewidths by stochastic noise and thermal sensitivity. In this work, we demonstrate a laser system with a 1-s linewidth of 1.1 Hz and fractional frequency instability below 10 to 1 s. This low-noise performance leverages integrated lasers together with an 8-ml vacuum-gap cavity using microfabricated mirrors. All critical components are lithographically defined on planar substrates, holding potential for high-volume manufacturing. Consequently, this work provides an important advance toward compact lasers with hertz linewidths for portable optical clocks, radio frequency photonic oscillators, and related communication and navigation systems.
在秒级时间尺度上具有赫兹线宽的激光器对于计量学、计时以及量子系统的操控至关重要。这种频率稳定性依赖于体光学激光器和参考腔，在其中增大尺寸可用于降低噪声，但要付出成本、人工组装以及应用受限的代价。另外，基于平面波导的激光器具有互补金属氧化物半导体的可扩展性，然而由于随机噪声和热灵敏度，从根本上限制了其实现赫兹线宽。在这项工作中，我们展示了一种激光系统，其1秒线宽为1.1赫兹，分数频率不稳定性低于10的负11次方/秒。这种低噪声性能利用了集成激光器以及使用微加工反射镜的8毫升真空间隙腔。所有关键组件都通过光刻在平面衬底上定义，具有大规模制造的潜力。因此，这项工作朝着具有赫兹线宽的紧凑型激光器迈出了重要一步，可用于便携式光学时钟、射频光子振荡器以及相关的通信和导航系统。
