TY - JOUR

T1 - Free-space interferometer design for optical frequency dissemination and out-of-loop characterization below the 10−21-level

AU - Jürss, Thomas

AU - Grosche, Gesine

AU - Koke, Sebastian

N1 - Funding Information: Deutsche Forschungsgemeinschaft (CRC 1464 Terra-Q (Project-ID 434617780), EXC-2123 Quantum Frontiers (Project-ID 390837967)); European Metrology Programme for Innovation and Research (18SIB06 TiFOON). We thank Alexandre Didier and Tanja Mehlstäubler for providing the UV curable adhesive, the group of Uwe Sterr and Tim Müller from the Department of Hydrology and River Basin Management of the Technical University Braunschweig for providing the air pressure measurements. We are grateful to Thomas Legero and Uwe Sterr for the PT100 temperature sensor calibration. We acknowledge fruitful discussions with Jochen Kronjäger, Erik Benkler, Alexander Kuhl, Thomas Waterholter, Andreas Koczwara (all PTB), Gudrun Wanner (AEI), Stephan Anders and Peter Zimmermann (both Layertec). The published work is part of the TiFOON project. This project has received funding from the EMPIR programme co-financed by the Participating States and from the European Union's Horizon 2020 research and innovation programme. In addition, we received funding from the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) under Germany's Excellence Strategy Quantum Frontiers.

PY - 2023/6

Y1 - 2023/6

N2 - For improving the performance of optical frequency dissemination and the resolution of its out-of-loop (OOL) characterization, we investigate a compact free-space interferometer design in which a monolithic assembly forms the reference arm. Two interferometer designs are realized, and their environmental sensitivity is analyzed based on the properties of the materials involved. We elucidate that in these designs the temperature sensitivities of the out-of-loop signal paths are greater than for the reference arm. As the estimated temperature-variation-induced frequency transfer errors are observed to be the relevant limitation, the out-of-loop characterization signal can be regarded as a trustworthy upper limit of the frequency transfer error to a remote place. We demonstrate a fractional frequency transfer uncertainty and OOL characterization resolution of ≤2.7 × 10 −21 over many measurement runs. With a value of (0.23 ± 1.07) × 10 −22 the weighted mean offset is significantly below the best reported results so far.

AB - For improving the performance of optical frequency dissemination and the resolution of its out-of-loop (OOL) characterization, we investigate a compact free-space interferometer design in which a monolithic assembly forms the reference arm. Two interferometer designs are realized, and their environmental sensitivity is analyzed based on the properties of the materials involved. We elucidate that in these designs the temperature sensitivities of the out-of-loop signal paths are greater than for the reference arm. As the estimated temperature-variation-induced frequency transfer errors are observed to be the relevant limitation, the out-of-loop characterization signal can be regarded as a trustworthy upper limit of the frequency transfer error to a remote place. We demonstrate a fractional frequency transfer uncertainty and OOL characterization resolution of ≤2.7 × 10 −21 over many measurement runs. With a value of (0.23 ± 1.07) × 10 −22 the weighted mean offset is significantly below the best reported results so far.

UR - http://www.scopus.com/inward/record.url?scp=85164623070&partnerID=8YFLogxK

U2 - 10.1364/prj.485899

DO - 10.1364/prj.485899

M3 - Article

VL - 11

SP - 1113

EP - 1124

JO - Photonics research

JF - Photonics research

SN - 2327-9125

IS - 6

ER -