Noise level of a ring laser gyroscope in the femto-rad/s range

• Published in: arXiv.org
• Main Authors: Angela D V Di Virgilio, Bajardi, Francesco, Basti, Andrea, Beverini, Nicolò, Carelli, Giorgio, Ciampini, Donatella, Giuseppe Di Somma, Fuso, Francesco, Maccioni, Enrico, Marsili, Paolo, Ortolan, Antonello, Porzio, Alberto, Vitali, David
• Format: Paper Journal Article
• Language: English
• Published: Ithaca Cornell University Library, arXiv.org 07.06.2024
• Subjects: Lasers; Noise propagation; Noise sensitivity; Physics - General Relativity and Quantum Cosmology; Physics - Optics; Physics - Quantum Physics; Propagation modes; Ring laser gyroscopes
• ISSN: 2331-8422
• DOI: 10.48550/arxiv.2301.01386

Absolute angular rotation rate measurements with sensitivity better than prad/s would be beneficial for fundamental science investigations. On this regard, large frame Earth based ring laser gyroscopes are top instrumentation as far as bandwidth, long--term operation, and sensitivity are concerned. Here, we demonstrate that the GINGERINO active--ring laser upper limiting noise is close to \(2 \times 10^{-15}\) rad/s for \(\sim 2 \times 10^5\) s of integration time, as estimated by the Allan deviation evaluated in a differential measurement scheme. This is more than a factor 10 better than the theoretical prediction so far accounted for ideal ring lasers shot--noise with the two beams counter--propagating inside the cavity considered as two independent propagating modes. This feature is related to the peculiarity of real ring laser system dynamics that causes phase cross--talking among the two counter--propagating modes. In this context, the independent beam model is, then, not applicable and the measured noise limit falls below the expected one.