Multi-core fiber microbend sensor

Abstract

The invention discloses a multi-core fiber microbend sensor. The sensor comprises a fixed pipe sleeve, a multi-core fiber, and a deformer, wherein the fixed pipe sleeve is made of a rigid material, the multi-core fiber is arranged in the middle of the fixed pipe sleeve, a clearance between the fixed pipe sleeve and the multi-core fiber is filled with a flexible material, the fixed pipe sleeve andthe deformer are connected through an elastomer structure, the deformer is made of the rigid material, and the deformer is provided with periodic deformation teeth. External pressure is transferred toa fiber microbend deformer through deformation of the deformer, so that the periodic deformation teeth in the fiber microbend deformer act on the multi-core fiber in the fixed pipe sleeve, then the multi-core fiber bends slightly, different fiber cores in the multi-core fiber have different curvature radiuses of microbending due to different spatial positions, therefore, different fiber cores aredifferent in microbending loss, external pressure and direction change can be learnt according to losses of optical signals in different fiber cores, and external pressure and direction can be sensedat the same time.

Description

technical field [0001] The invention relates to a multi-core optical fiber micro-bending sensor, relates to the technical field of optical fiber sensing, in particular to a pressure micro-bending sensor based on a multi-core optical fiber, capable of measuring the magnitude and direction of external pressure. Background technique [0002] When light is transmitted in the optical fiber, the phase and amplitude of the light wave will change due to external temperature, pressure, vibration and other factors. The optical fiber sensor is a sensor that uses this principle to detect changes in physical quantities. Since the optical path of the optical fiber is closed, the optical fiber sensor is more suitable for measurement in harsh environments such as high temperature and high pressure, flammable, explosive, and corrosive conditions. Therefore, fiber optic sensors have been widely used in aerospace, oil exploration, automatic control and other fields. [0003] As an important o...

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Problems solved by technology

[0004] Although the optical fiber micro-bend pressure sensor has many unique advantages such as small size, light weight, strong anti-electromagnetic interference ability, and ability to adapt to harsh working environments (Liu Changhua, Xu Yajun. Distributed optical fiber stress based on optical time domain reflectometry Sensors. [J]. Instrument Technology and Sensors, 2005, 3(6): 3-5.), but the existing optical fiber microbending pressure sensors still have certain defects, for example, a single optical fiber microbending pressure sensor can only detect The magnitude of the pressure in a fixed direction, but the direction of the pressure cannot be sensed

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