This work demonstrates that a middle size ring laser gyroscope (RLG) can be a very sensitive and robust instrument for rotational seismology, even if it operates in a quite noisy environment. The RLG has a square cavity, 1.60×1.60 m2, and it lies in a plane orthogonal to the Earth rotational axis. The Fabry-Perot optical cavities along the diagonals of the square were accessed and their lengths were locked to a reference laser. Through a quite simple locking circuit, we were able to keep the sensor fully operative for 14 days. The obtained long term stability is of the order of 3~nanorad/s and the short term sensitivity close is to 2~nanorad/s⋅Hz−1/2. These results are limited only by the noisy environment, our laboratory is located in a building downtown.
@article{arxiv.2207.04942,
title = {A high sensitivity tool for geophysical applications: A geometrically locked Ring Laser Gyroscope},
author = {E. Maccioni and N. Beverini and G. Carelli and G. Di Somma and A. Di Virgilio and P. Marsili},
journal= {arXiv preprint arXiv:2207.04942},
year = {2022}
}