White-light interferometric optical fiber gravimeter

Abstract

The invention discloses a white-light interferometric optical fiber gravimeter which comprises a white light source, a polarization-maintaining beam splitter, a gravity sensing device, a phase modulator and a photoelectric detector; the white light source is connected with one inlet end of the polarization-maintaining beam splitter through a polarization-maintaining fiber; two outlet ends of the polarization-maintaining beam splitter are connected with two inlet ends of the gravity sensing device respectively through polarization-maintaining fibers; two outlet ends of the gravity sensing device are connected with two inlet ends of the phase modulator respectively through polarization-maintaining fibers; an outlet end of the phase modulator is connected with the photoelectric detector through a polarization-maintaining fiber; and the white light source is connected with the polarization-maintaining beam splitter through a 0-degree counter shaft of the polarization-maintaining fiber, and the polarization-maintaining beam splitter is connected with the gravity sensing device through the 0-degree counter shaft of the polarization-maintaining fiber. By using the white-light interferometry, the white-light interferometric optical fiber gravimeter reduces the impact of backscattering and reduces the coherent noise by adopting the broadband light source, and greatly improves the polarization error caused by polarization cross-coupling and greatly enhances the system accuracy (The accuracy can reach 10-9 g) by adopting the all-polarization-maintaining system.

Description

technical field [0001] The invention relates to an optical fiber sensing technology, in particular to a white light interference optical fiber gravimeter. Background technique [0002] A gravimeter is an instrument for measuring the acceleration of gravity and is the main means of detecting the information of the earth's gravitational field. It plays a key role in the establishment of national gravity reference points, earthquake and sea level monitoring, precise determination of the geoid, vertical deformation of the earth's crust, and national defense construction. [0003] High-precision gravity detection can accurately obtain the change characteristics related to material migration and crustal movement in the earth's interior, and provide an important basis for geodesy, geophysics, the dynamic mechanism of the earth's interior, environment and disaster monitoring. At present, many countries in the world have established absolute gravity networks to monitor non-tidal cha...

AI Technical Summary

Problems solved by technology

However, the uncontrolled arm length is likely to cause the influence of the environment (such as temperature) on the phase, and introduce coherent noise (such as backscattering)

At the same time, the phase error caused by the polarization cross-coupling of the narrowband light source will also greatly affect the accuracy of the fiber optic gravimeter.

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