A laser gyroscope system to detect the gravito-magnetic effect on Earth

The Sagnac effect and pure geometry

“…[4] The extremely high sensitivity obtained in most recent ring lasers is such that now the Sagnac effect is becoming important also for fundamental physics: the possibility has been suggested of using large ring lasers to detect the Lense-Thirring effect on Earth [5] and an experiment, under the acronym GINGER, is now in the phase of development and preliminary testing at the National Laboratories of the Italian INFN at the Gran Sasso site. [6] [7] The Sagnac effect plays a role also in the elaboration of the position of a receiver obtained from the GPS: a Sagnac correction is indeed required because a rotating clock (onboard a satellite or on the surface of the earth) suffers a loss of synchrony with itself at each turn.…”

A note on the Sagnac effect and current terrestrial experiments

“…Today, the Sagnac effect is important also for fundamental physics. In fact large ring lasers can be used for an independent determination of the Lense-Thirring effect, in an Earth based experiment [17][18][19]: these devices measure with great accuracy the rotation rate of the terrestrial laboratory where they are located with respect to an inertial frame, e.g. with respect to fixed stars and, in doing so, the gravitational drag of inertial frames comes into play (see for instance [20,21]).…”

A network of heterodyne laser interferometers for monitoring and control of large ring-lasers

“…GINGER (Gyroscopes IN GEneral Relativity) is an experiment proposal for the first time on ground measurement of the Earth induced LT effect. [7][8][9][10] More specifically, GINGER will consist of an array of at least three mutually orthogonal square ring-lasers (6-10 m in side), arranged, for instance, in a cubic or octahedral configuration, as shown in Figure 1a and Figure 1b. The tri-axial design will provide a complete estimation of the laboratory frame angular velocity.…”