Universal pressure sensing device based on optical fiber microbending loss

Abstract

The invention discloses a universal pressure sensing device based on an optical fiber microbending loss, which comprises a cylindrical cavity, wherein one end of the cylindrical cavity is closed by a substrate, and the other end of the cylindrical cavity is fixedly provided with a corrugated piece; and a multi-layer microbending element containing a signal optical fiber is fixedly arranged between the substrate and the corrugated piece. When the tested pressure acts on the corrugated piece, the corrugated piece deforms and transfers the force to the multi-layer microbending element to allow the multi-layer microbending element to be compressed, so that the bending curvature of the signal optical fiber contained in the multi-layer slightly bent element changes, and thus the power of optical signals transmitted in the signal optical fiber is obviously changed, and the pressure is tested by the detection of a testing unit. The multi-layer microbending loss element is adopted, so that the effective length of the signal optical fiber is lengthened, the bending curvature of the signal optical fiber is reduced, and thus the precision of the device is improved, the service life of the signal optical fiber is substantially prolonged simultaneously, and the device has broad application prospects.

Description

technical field [0001] The invention relates to a pressure sensing device, in particular to a universal pressure sensing device based on multilayer optical fiber microbend loss. Background technique [0002] There are many types of optical fiber pressure sensing devices, mainly including light intensity modulation optical fiber sensing devices, fiber grating pressure sensing devices, optical fiber interference pressure sensing devices, etc. The latter two are characterized by sensing sensitivity However, in the actual application process, there are defects and deficiencies such as complex equipment and high operating costs, which greatly restrict the application and promotion of optical fiber sensing devices. In the optical intensity modulation optical fiber pressure sensing device, there are mainly membrane reflection type or microbending loss type structure. The main defect of the former is that the optical fiber is discontinuous in the sensing device, and there is a prob...

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Problems solved by technology

The main defect of the former is that the optical fiber is discontinuous in the sensing device, and there is a problem of end surface pollution, which affects the long-term use accuracy of the optical fiber sensing device. Loss type device, two sawtooth plates that have been strictly processed are placed in parallel, and the optical fiber is clamped between the two parallel sawtooth plates. The deformation of the optical fiber in this device is very small, only a few hundred microns, resulting in a small detection range, which limits its practicality. and scope of application; another type is Chinese patent 93206204.0 "optical fiber sensing pressure head", and the article "optical fiber based on C-type spring tube and optical fiber ring" in Journal of Xi'an University of Technology (2000) Vol.16No.1p.69-73 Proposed in "Pressure Sensor": The optical fiber disk is made into an optical fiber ring with a diameter of about 5-10mm, and placed between the fixed bracket and the C-shaped spring tube through the clamp. When there is a pressure change, the position of the C-shaped spring tube is relatively Due to the change of the fixed bracket, the bending curvature of the fiber ring is changed, resulting in the change of the bending loss of the optical signal transmitted by the optical fiber in the fiber ring. By detecting the change of the bending loss, the change of the monitoring pressure can be obtained, but in the two devices The optical fiber ring requires a diameter of about 5-10mm, and most optical fibers will have a large bending internal stress under this bending curvature, and the optical fiber will break in a short time, resulting in the failure of the optical fiber sensor. The practicality and popularization of this kind of sensor

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