Two-dimension high-precision combined interference type fiber integrated accelerometer

Abstract

The invention provides a two-dimension high-precision combined interference type fiber integrated accelerometer comprising two light sources with the wavelengths of Lambda1 and Lambda2, a wavelength division multiplexer, a circulator, a single-core optical fiber, an optical fiber sensing probe, a demultiplexer 7 and two detectors with the wavelengths of Lambda1 and Lambda2, wherein the optical fiber sensing probe comprises a fused embedded polarization maintaining optical fiber containing four fiber cores which are vertical to each other and are symmetrically distributed; each fiber core of the fused embedded polarization maintaining optical fiber is marked with a pair of Bragg optical fiber gratings with equal reflection centre wavelengths to form an F-P (Fabry-Perol) chamber; the resonance wavelengths of the four optical fiber gratings on the two opposite fiber cores are Lambda1, and the resonance wavelengths of the four optical fiber gratings on the two fiber cores orthogonal with the two opposite fiber cores are Lambda2. In the invention, a combined type interferometer comprising two mutually orthogonal double-F-P chamber Michelson interferometers is formed in the same polarization maintaining optical fiber to measure two-dimension acceleration. The accelerometer has the advantages of high system integrated level, single-optical fiber integration, high sensitivity, good polarization maintaining characteristic and the like.

Description

technical field [0001] The invention relates to an optical fiber accelerometer. Background technique [0002] Accelerometer is an important sensor commonly used in anti-shock and anti-vibration measurement of vehicles and ships, earthquake detection, inertial navigation and guidance system. The resulting inertial force or displacement can be measured to measure the corresponding acceleration. Traditional accelerometers use electromechanical methods to measure the inertial force or displacement of the mass, while fiber optic accelerometers use fiber optic sensing technology to measure the inertial force or displacement of the mass. Compared with the former, the latter not only has the unique advantages of anti-electromagnetic interference, but also has small size and light weight, wide dynamic range, high precision, can work in harsh environments, and is easy to detect in long-distance networking. It is especially suitable for applications requiring high-performance accelera...

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Problems solved by technology

Chinese patent "dual-core optical fiber integrated accelerometer and measurement method" (public number CN 101368978) uses CCD to measure the change of dual-core optical fiber transmission interference fringes to measure acceleration, the system integration level is greatly improved, but the pixel requirements of CCD are very high

The Chinese patent "Fiber Bragg Grating Three-dimensional Acceleration Vibration Sensor" (publication number CN 101210937 A) and the US patent US20060219009A1 use three fiber gratings to achieve three-dimensional acceleration measurement. The probe structure designed by this method is too complicated and the system volume is large, which is not conducive to practical use

People such as domestic Rao Yunjiang have also proposed multiple structural fiber F-P interferometers and manufacturing methods thereof (CN101055196, CN 101034007), and applied it in the accelerometer (CN 101424697 A, CN 101368979A), but the acceleration structures proposed are all one dimension measurement

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