A ring-laser-gyro (RLG) is a rotation sensor based on the Sagnac effect. Its ultimate sensitivity is given by the shot-noise. RLG are ring optical cavities where an in-cavity optically active laser volume emits two counter propagating beams. They, if the cavity is rotating and due to the Sagnac effect, show different frequencies. This frequency difference is proportional to the rotation rate of the ring itself. Here we present noise floor measurement for a large ring laser showing that the reached sensitivity level is not consistent with an independent beam model. The measured sensitivity is, indeed, about one order of magnitude better than expected. This is most probably due to coupling of the phases of the two beams mediated by the laser medium and mirror back-scattering. This result paves the way to the use of large RLGs in a wide range of measures in fundamental physics as well as to experimentally investigating quantum effects in non-inertial reference frames. In this contribution, starting from the experimental findings, we will discuss the necessary modifications to the theory and give some hints to understand the role of the above-mentioned mechanisms.
Redefining the limiting noise for a high sensitivity ring laser gyro
Basti, Andrea;Beverini, Nicolò;Carelli, Giorgio;Di Somma, Giuseppe;Fuso, Francesco;Maccioni, Enrico;Marsili, Paolo;
2024-01-01
Abstract
A ring-laser-gyro (RLG) is a rotation sensor based on the Sagnac effect. Its ultimate sensitivity is given by the shot-noise. RLG are ring optical cavities where an in-cavity optically active laser volume emits two counter propagating beams. They, if the cavity is rotating and due to the Sagnac effect, show different frequencies. This frequency difference is proportional to the rotation rate of the ring itself. Here we present noise floor measurement for a large ring laser showing that the reached sensitivity level is not consistent with an independent beam model. The measured sensitivity is, indeed, about one order of magnitude better than expected. This is most probably due to coupling of the phases of the two beams mediated by the laser medium and mirror back-scattering. This result paves the way to the use of large RLGs in a wide range of measures in fundamental physics as well as to experimentally investigating quantum effects in non-inertial reference frames. In this contribution, starting from the experimental findings, we will discuss the necessary modifications to the theory and give some hints to understand the role of the above-mentioned mechanisms.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.