The measurement of rotational components in seismic waves holds significant importance in various fields, including seismic early warning, subsurface structure inversion, and the study of Earth's internal dynamic processes. The interferometric fiber optic gyroscope (IFOG) is a kind of sensor that measures the rotational velocity of an object based on the Sagnac effect. In this study, a synchronous four-state modulation scheme based on a light source sharing configuration is employed to suppress RIN. Moreover, this work extensively investigates the impact of shot noise and Johnson-Nyquist noise. By adjusting the modulation depths of the two minimum configurations, the influence of shot noise and Johnson-Nyquist noise is well-handled while achieving RIN suppression. Furthermore, this scheme avoids introducing any external feedback, thereby preventing a decrease in sensitivity caused by the dead zone issue. In a test on detecting the rotation rate of the Earth, a self-noise level of 55 nrad/s/Hz1/2 and an angular random walk of 1.5 × 10−4 deg/h1/2 are achieved with an enclosed area of only 25.5 m2. Compared to the minimum configuration using the conventional phase generated carrier algorithm, the scheme realizes a 20-fold reduction in self-noise and an 18- fold reduction in angular random walk.
We propose and implement a source-sharing configuration based on fiber-optic gyroscopes for differential-mode and common-mode measurements. By adopting suitable values of the modulation parameters, the effect of relative intensity noise and thermal phase noise can be suppressed. Experimental results show that this configuration can achieve a maximum of 5.78 times self-noise suppression. We also show that the deviation of the modulation frequency from the eigenfrequency or its harmonics leads to an increase of the self-noise level. A deviation of 400 Hz can lead to a degradation of the self-noise level by up to 2.38 times. Finally, we prove the ability of suppression the environmental disturbance through an observation with the effect of natural vibrations.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.