具有晶体涂层的低温蓝宝石光学参考腔，分数频率不稳定性为1×10⁻¹⁶ 。

Cryogenic sapphire optical reference cavity with crystalline coatings at 1 × 10-16 fractional frequency instability.

作者信息

Valencia Jose, Iskander George, Nardelli Nicholas V, Leibrandt David R, Hume David B

机构信息

National Institute of Standards and Technology, Boulder, Colorado 80302, USA.

Department of Physics, University of Colorado, Boulder, Colorado 80309, USA.

出版信息

Rev Sci Instrum. 2024 Oct 1;95(10). doi: 10.1063/5.0214790.

DOI:10.1063/5.0214790

PMID:39356190

Abstract

The frequency stability of a laser locked to an optical reference cavity is fundamentally limited by thermal noise in the cavity length. These fluctuations are linked to material dissipation, which depends on both the temperature of the optical components and the material properties. Here, the design and experimental characterization of a sapphire optical cavity operated at 10 K with crystalline coatings at 1069 nm is presented. Theoretical estimates of the thermo-mechanical noise indicate a thermal noise floor below 4.5 × 10-18. Major technical noise contributions including vibrations, temperature fluctuations, and residual amplitude modulation are characterized in detail. The short-term performance is measured via a three-cornered hat analysis with two other cavity-stabilized lasers, yielding a noise floor of 1 × 10-16. The long-term performance is measured against an optical lattice clock, indicating cavity stability at the level of 2 × 10-15 for averaging times up to 10 000 s.

摘要

锁定到光学参考腔的激光器的频率稳定性从根本上受到腔长度热噪声的限制。这些波动与材料耗散有关，而材料耗散取决于光学元件的温度和材料特性。本文介绍了一个在10 K下运行、具有1069 nm晶体涂层的蓝宝石光学腔的设计和实验表征。热机械噪声的理论估计表明热噪声本底低于4.5×10⁻¹⁸。详细表征了包括振动、温度波动和残余幅度调制在内的主要技术噪声贡献。通过与另外两台腔稳定激光器进行三角帽分析来测量短期性能，得出噪声本底为1×10⁻¹⁶。相对于光晶格钟测量长期性能，表明在平均时间长达10000 s时，腔的稳定性达到2×10⁻¹⁵水平。