Work

Local Determination of Comb Mode Number in Remote Optical Clock Comparison

Year: 2026

Type: article

Abstract: Optical clocks and their associated frequency comparison networks are exceptionally sensitive to microscopic physical variations and thus capable of measuring fundamental physical quantities across diverse applications. In frequency comparison networks, the optical frequency combs (OFCs) act as accurate frequency sensors designed to translate terahertz optical signals down to radio frequency signals for accurate frequency counting. The number of OFC's comb modes that beat with clock and transfer lasers during remote frequency comparison is indispensable for the calculation of their frequency difference. In this work, with the assistance of a 1542 nm cavity-stabilized laser at Changping campus, the number of comb modes is locally determined with sufficient uncertainty by stepping the comb's repetition rate. This approach bypasses the technical challenges of simultaneous operation of optical clocks, OFC and fiber-link noise cancelation during long-distance comparison, providing a reliable prerequisite for remote optical clock comparisons.

Source: Sensors

DOI: 10.3390/s26175360

Authors: Hao Liu, Haochen Tian, Bingkun Lu, Qiang Wang, Yige Lin

Institutions: Tongji University, National Institute of Metrology, State Administration for Market Regulation

Language: English

Topic: Advanced Frequency and Time Standards

Subfield: Atomic and Molecular Physics, and Optics

Field: Physics and Astronomy

Domain: Physical Sciences

Open Access status: gold

Estimated APC paid: $3,137

Funders: National Natural Science Foundation of China, National Institute of Metrology, China