Method and device for inquiring signals by unbalanced Mach-Zehnder interferometer

Abstract

The invention discloses a method and a device for inquiring a plurality of signals by an unbalanced Mach-Zehnder interferometer. The device consists of a wide-spectrum light source, a three-port circulator, a photoelectric detector, the unbalanced Mach-Zehnder interferometer, a single-mode connection optical fibre and a serial optical fibre sensor array, wherein the wide-spectrum light source andthe photoelectric detector form transmitting and receiving photoelectric devices through the three-port circulator; the unbalanced Mach-Zehnder interferometer consists of a scanning prism, a half-reflecting and half-transmitting mirror and a self-focusing lens; and the serial optical fibre sensor array is an end-to-end serial array formed by a series of single-mode optical fibre sections which are unequal in length. The invention has the advantages of simple structure, easy implementation, convenient use, low cost, expansion of a distributed measuring method, adjustable dynamic range and accuracy, relatively strong anti-interference and the like. The method and the device can be used for sensing detection on physical quantities such as distributed deformation, strain, a temperature and a pressure.

Description

technical field [0001] The invention belongs to the field of optical fiber technology, and in particular relates to a method for interrogating multiple sensor signals based on an unbalanced Mach-Zehnder interferometer, and a quasi-distributed optical fiber white light interference strain sensing demodulation device constructed based on the method. Background technique [0002] Fiber-optic interferometers driven by low-coherence, broad-spectrum light sources such as light-emitting diodes (LEDs), superspontaneous emission sources (ASEs), or superluminescent laser diodes (SLDs) are often referred to as fiber-optic white-light interferometers. A typical fiber optic white light interferometer such as figure 1 As shown, its structural composition is to use optical fiber to build a Micheslon interferometer, and use a wide-spectrum light source LED or ASE to drive the interferometer to provide light energy, and use the detector to detect white light interference fringes to achieve t...

AI Technical Summary

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 resonant cavity, and the loss will be too large, which will cause the signal attenuation to be too large and the amplitude to be too small to be demodulated. Application brings some trouble

In addition, the too long scanning arm is more sensitive to the ambient temperature, which will affect the accuracy of the measurement and is not conducive to the stability of the system.

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