A high sensitivity tool for geophysical applications: A geometrically locked Ring Laser Gyroscope

Abstract

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, $1.60\times 1.60$ m${}^2$, 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$\cdot$Hz${}^{-1/2}$. These results are limited only by the noisy environment, our laboratory is located in a building downtown.

9 pages, 4 figures, 25 references

References in corpus (3)

• The Sagnac effect: 20 years of development in matter-wave interferometry
• A large scale passive laser gyroscope for Earth rotation sensing
• Optimization of the geometrical stability in square ring laser gyroscopes