Microbend optical fiber sensor based on twin-core optical fiber

Abstract

The invention aims to provide a microbend optical fiber sensor based on a twin-core optical fiber. The microbend optical fiber sensor comprises a light source, a single-mode optical fiber coupler, the twin-core optical fiber, a first optical power meter and a second optical power meter. Light emitted by the light source is divided into two beams of light through the single-mode optical fiber coupler, the two output ends of the single-mode optical fiber coupler are connected with two fiber cores of the input end of the twin-core optical fiber respectively, the two beams of light are injected into the two fiber cores respectively and then transmitted to the first optical power meter and the second optical power meter through a first conduction single-mode optical fiber and a second conduction single-mode optical fiber respectively, and the first optical power meter and the second optical power meter input detected signals to an angle calculating circuit to obtain the bending angles of the two fiber cores. The distance between the two fiber cores is reduced, the coupling capacity of the two fiber cores is improved, and therefore the accuracy and sensitivity of the microbend optical fiber sensor are improved.

Description

technical field [0001] The invention relates to a sensor, in particular to a sensor for measuring micro-bending angles. 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 basic 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 are widely used in aerospace, oil exploration, automatic control and other fields. [0003] The fiber optic microbend sensor is one of the devices that measures the tiny bending of objects. Environmental parameters such as pressure, velocity, strain, flow, etc. are measured by bending the optical f...

AI Technical Summary

Problems solved by technology

However, the optical fiber microbend angle sensor based on light intensity changes has low accuracy and sensitivity, especially in the case of small angles, the loss of transmitted light intensity changes less, and accompanied by light source power fluctuations, which greatly affects the microbend Angle measurement results

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