Quasi-distribution optical fiber white-light strain sensing and demodulation device based on nonequilibrium Michelson interferometer

Abstract

The invention provides a quasi-distribution optical fiber white-light strain sensing and demodulation device based on a nonequilibrium Michelson interferometer. The device consists of a photoelectric device, a nonequilibrium Michelson interferometer, a single mode connection optical fiber and a serial optical fiber sensor array, wherein the photoelectric device consists of a broadband light source, a three-port circulator and a photoelectric detector; the nonequilibrium Michelson interferometer consists of a plated optical fiber reflection end, a scanning reflection mirror, a focusing lens and a 3dB optical fiber 2x2 coupler; and the serial optical fiber sensor array is formed by connecting optical fiber sensors in series. The device has the advantages of simple structure, convenience of use, low production cost, distributed measurement expansion, wide dynamic measurement range, high measurement precision, high anti-interference performance and the like, can sense and detect physical values such as distributed deformation, strain, temperature, pressure and the like, and can be used for monitoring intelligent structures in large sizes, and sensing a plurality of tasks, a plurality of elements, local strain and large-scale deformation.

Description

technical field [0001] The invention belongs to the field of optical fiber technology, and in particular relates to a distributed optical fiber white light interference strain sensing demodulation device for interrogating multiple sensor signals based on an unbalanced Michelson interferometer. Background technique [0002] Fiber-optic interferometers driven by low-coherence, broadband light sources such as light-emitting diodes (LEDs), superspontaneous emission sources (ASEs) or superluminescent laser diodes (SLDs) are often referred to as white-light fiber interferometers. The structure of a typical fiber optic white light interferometer is as follows: figure 1 As shown, the Michelson-type interferometer built by single-mode optical fiber uses a wide-spectrum light source LED or ASE as the light source, and realizes the measurement of the physical quantity to be measured through the white light interference fringes detected by the detector. Its working principle is as foll...

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Problems solved by technology

Otherwise, in order to match the excessively large optical path difference between the two arms of the interferometer, the scanning signal light will reflect too many times in the reson

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