Ring laser gyroscope

About: Ring laser gyroscope is a research topic. Over the lifetime, 2070 publications have been published within this topic receiving 18609 citations. The topic is also known as: Sagnac interferometer.

Ring-laser gyroscope without the lock-in phenomenon

Abstract: We theoretically and numerically study the effect of backscattering on rotating ring lasers by employing the Maxwell-Bloch equations. We show that frequency shifts due to the Sagnac effect incorporating the effect of backscattering can be observed without lock-in phenomenon, if the strength of backscattering originating in the bumps of the refractive index is larger than a certain value. It is also shown that the experimental results corresponding to the theoretical ones can actually be obtained by using a semiconductor fiber-optic ring laser gyroscope.

Controlling the non-linear intracavity dynamics of large He–Ne laser gyroscopes

Abstract: A model based on Lamb's theory of gas lasers is applied to a He–Ne ring laser (RL) gyroscope to estimate and remove the laser dynamics contribution from the rotation measurements. The intensities of the counter-propagating laser beams exiting one cavity mirror are continuously observed together with a monitor of the laser population inversion. These observables, once properly calibrated with a dedicated procedure, allow us to estimate cold cavity and active medium parameters driving the main part of the non-linearities of the system. The quantitative estimation of intrinsic non-reciprocal effects due to cavity and active medium non-linear coupling plays a key role in testing fundamental symmetries of space–time with RLs. The parameter identification and noise subtraction procedure has been verified by means of a Monte Carlo study of the system, and experimentally tested on the G-PISA RL oriented with the normal to the ring plane almost parallel to the Earth's rotation axis. In this configuration the Earth's rotation rate provides the maximum Sagnac effect while the contribution of the orientation error is reduced to a minimum. After the subtraction of laser dynamics by a Kalman filter, the relative systematic errors of G-PISA reduce from 50 to 5 parts in 103 and can be attributed to the residual uncertainties on geometrical scale factor and orientation of the ring.

Ring laser gyro system

Abstract: A laser gyro system is disclosed wherein the lock-in error associated with the sensor signal deriving phase information of the phase relationship between a pair of lasing beams therein is accounted for and utilized for correction and/or control.

A 1.82 m^2 ring laser gyroscope for nano-rotational motion sensing

Abstract: We present a fully active-controlled He-Ne ring laser gyroscope, operating in square cavity 1.35 m in side. The apparatus is designed to provide a very low mechanical and thermal drift of the ring cavity geometry and is conceived to be operative in two different orientations of the laser plane, in order to detect rotations around the vertical or the horizontal direction. Since June 2010 the system is active inside the Virgo interferometer central area with the aim of performing high sensitivity measurements of environmental rotational noise. So far, continuous not attempted operation of the gyroscope has been longer than 30 days. The main characteristics of the laser, the active remote-controlled stabilization systems and the data acquisition techniques are presented. An off-line data processing, supported by a simple model of the sensor, is shown to improve the effective long term stability. A rotational sensitivity at the level of ten nanoradiants per squareroot of Hz below 1 Hz, very close to the required specification for the improvement of the Virgo suspension control system, is demonstrated for the configuration where the laser plane is horizontal.

Distributed sagnac sensor systems

Abstract: Wavelength division multiplexed Sagnac distributed sensor systems that allow the determination of the position and amplitude of a frequency dependent environmental effect acting on the optical path of Sagnac loops. The sensor includes two Sagnac interferometers operating at different wavelengths and having optically spaced combining couplers and optical loops which include as portions thereof, the optical path. The outputs of the Sagnac interferometers are summed to determine the relative amplitude of the sensed effect and compared to determine its position on the optical path.