Optical fiber acceleration measuring device based on fiber core mismatch

Abstract

The invention provides an optical fiber acceleration measuring device based on fiber core mismatch. The device is composed of a light source, a single-mode optical fiber, an optical circulator, an accelerometer based on fiber core mismatch, a photoelectric detector and a signal processing device. The accelerometer is formed by sequentially welding a single-mode optical fiber, a large-core-diameteroptical fiber and a double-clad optical fiber with an inclined grating, and the welded optical fiber penetrates through a preformed hole of the mounting plate and is arranged in the elastic sleeve. Light emitted by the light source is input from the end a of the circulator and output from the end b through the single-mode optical fiber, the end b is connected with the accelerometer, and light reflected by the inclined grating is input into the port c through the port b of the circulator, output to the photoelectric detector, converted into electric signals and finally processed by the signalprocessing device. When the external vibration frequency is changed, the resonance peak of the inner cladding of the double-cladding fiber inclined grating is changed, and the vibration frequency andacceleration of an object are measured by monitoring the resonance peak. The measuring device has the advantages of the small volume, fast response, no temperature influence and the like.

Description

[0001] (1) Technical field [0002] The invention relates to an optical fiber acceleration measurement device based on fiber core mismatch, in particular to a reflective acceleration sensor based on a double-clad optical fiber tilt grating, which can measure vibration frequency and acceleration, and belongs to the technical field of optical fiber sensing. [0003] (2) Background technology [0004] Acceleration is a very important parameter index in the process of object motion, which characterizes and measures the dynamic characteristics of the object. Accurate measurement of acceleration is currently widely used in various technical fields such as mechanical vibration measurement, traffic monitoring, seismic wave signal detection for oil and gas exploration, building structure monitoring, and aerospace inertial navigation and guidance systems. [0005] Acceleration signal measurement usually uses the principle of inertia to measure the corresponding acceleration by sensing th...

AI Technical Summary

Problems solved by technology

However, this kind of grating-type wavelength measurement accelerometer is easily affected by changes in the external environment. For example, when the temperature changes, it will also cause the center wavelength to shift, resulting in cross-interference, and this method requires femtosecond finishing, which is difficult to manufacture. High cost, difficult to achieve mass production

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