Di Virgilio Angela D V, Bajardi Francesco, Basti Andrea, Beverini Nicolò, Carelli Giorgio, Ciampini Donatella, Di Somma Giuseppe, Fuso Francesco, Maccioni Enrico, Marsili Paolo, Ortolan Antonello, Porzio Alberto, Vitali David
<a href="https://ror.org/05symbg58">Istituto Nazionale di Fisica Nucleare Sez. di Pisa</a>, Largo Bruno Pontecorvo 3, I-56127 Pisa, Italy.
<a href="https://ror.org/015kcdd40">Istituto Nazionale di Fisica Nucleare Sez. di Napoli</a>, Compl. Univ. Monte S. Angelo, Edificio G, Via Cinthia, I-80126, Napoli, Italy.
Phys Rev Lett. 2024 Jul 5;133(1):013601. doi: 10.1103/PhysRevLett.133.013601.
Absolute angular rotation rate measurements with sensitivity better than prad/s would be beneficial for fundamental science investigations. In 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 2×10^{-15} rad/s for ∼2×10^{5} s of integration time, as estimated by the Allan deviation evaluated in a differential measurement scheme. This result is more than a factor of 10 better than the theoretical prediction so far accounted for ideal ring lasers shot-noise with the two beams counterpropagating 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 crosstalking among the two counterpropagating modes. In this context, the independent beam model is, then, not applicable, and the measured noise limit falls below the expected one.
对于基础科学研究而言，灵敏度优于prad/s的绝对角旋转速率测量将大有裨益。就此而言，就带宽、长期运行和灵敏度而言，大型框架地基环形激光陀螺仪是顶级仪器。在此，我们证明，通过在差分测量方案中评估的阿伦偏差估计，对于约2×10⁵秒的积分时间，GINGERINO有源环形激光器的上限噪声接近2×10⁻¹⁵rad/s。这一结果比迄今针对理想环形激光器散粒噪声的理论预测要好10倍以上，在理想环形激光器中，腔内反向传播的两束光被视为两个独立的传播模式。这一特性与实际环形激光系统动力学的特殊性有关，该特殊性会导致两个反向传播模式之间的相位串扰。在这种情况下，独立光束模型不再适用，测量到的噪声极限低于预期值。
