Analysis of ring laser gyroscopes including laser dynamics

Abstract

Inertial sensors stimulate very large interest, not only for their application but also for fundamental physics tests. Ring laser gyros, which measure angular rotation rate, are certainly among the most sensitive inertial sensors, with excellent dynamic range and bandwidth. Large area ring laser gyros are routinely able to measure fractions of prad/s, with high duty cycle and bandwidth, providing fast, direct and local measurement of relevant geodetic and geophysical signals. Improvements of a factor $10-100$ would open the windows for general relativity tests, as the GINGER project, an Earth based experiment aiming at the Lense-Thirring test at $1\%$ level. However, it is well known that the dynamics of the laser induces non-linearities, and those effects are more evident in small scale instruments. Sensitivity and accuracy improvements are always worthwhile, and in general there is demand for high sensitivity environmental study and development of inertial platforms, where small scale transportable instruments should be used. We discuss a novel technique to analyse the data, aiming at studying and removing those non-linearity. The analysis is applied to the two ring laser prototypes GP2 and GINGERINO, and angular rotation rate evaluated with the new and standard methods are compared. The improvement is evident, it shows that the back-scatter problem of the ring laser gyros is negligible with a proper analysis of the data, improving the performances of large scale ring laser gyros, but also indicating that small scale instruments with sensitivity of nrad/s are feasible.

arXiv comment9 pages and 7 figures

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Cited by in corpus (11)

• An underground Sagnac gyroscope with sub-prad/s rotation rate sensitivity: toward General Relativity tests on Earth
• Noise level of a ring laser gyroscope in the femto-rad/s range
• Reaching the sensitivity limit of a Sagnac gyroscope through linear regression analysis
• A high sensitivity tool for geophysical applications: A geometrically locked Ring Laser Gyroscope
• Overcoming 1 part in $10^9$ of Earth angular rotation rate measurement with the G Wettzell data
• Identification and correction of Sagnac frequency variations: an implementation for the GINGERINO data analysis
• GINGER
• Comparative analysis of local angular rotation between the Ring Laser Gyroscope GINGERINO and GNSS stations
• Stabilizing the free spectral range of a large ring laser
• Hänsch-Couillaud locking of a large Sagnac interferometer: advancing below the flicker floor
• Optical steering of a large ring laser