Space division multiplexing Mach-Zehnder cascade type optical fiber interferometer and measurement method thereof

Abstract

The invention provides a space division multiplexing Mach-Zehnder cascade fiber interferometer and a measurement method thereof. The space division multiplexing Mach-Zehnder cascade fiber interferometer is composed of a wide-spectrum light source, a photodetector, a coupler, a single-mode connection optical fiber, an optical fiber sensor, a continuous-variable optical delay device, and a reflector, wherein the optical fiber sensor is composed of a Mach-Zehnder interferometer and forms a cascade optical fiber sensor array or a network. The wide-spectrum light source and a photodetector are connected with the optical fiber sensor through the coupler to form a sensor network; and the sensor network is connected with the continuous-variable optical delay device and the reflector through the coupler and is used for enquiring and demodulating the optical fiber sensor. The space division multiplexing Mach-Zehnder cascade fiber interferometer solves the problem of breakage of the optical fiber sensor array, improves the anti-damage characteristics of the optical fiber sensor array and the network and solves the temperature compensation problem in the measurement process. The space division multiplexing Mach-Zehnder cascade fiber interferometer has the advantages of simple interferometer structure, easy implementation, improved measurement reliability and low cost, and better facilitates the technology generalization and popularization.

Description

(1) Technical field [0001] The invention relates to a measuring device, in particular to a space division multiplexing Mach-Zehnder cascaded optical fiber interferometer. (2) Background technology [0002] Fiber-optic interferometers using low-coherence, broadband light sources are often referred to as white-light fiber 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 the measurement of the physical quantity to be measured. Its working principle is as follows. After the broadband light emitted by the broadband light source 11 enters the single-mode fiber, it is divided into two beams by the 3dB single-mode fiber 2×2 coupler 13, and one beam enters the single-mode fiber 14...

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Problems solved by technology

[0012] In 2006, the inventor disclosed a multiplexing optical fiber interferometer and its nested construction method (Chinese patent publication number: CA1963399A), invented an all-fiber interferometer optical fiber and its implementation method that can construct sensor arrays and networks, and solved the problem of optical fiber The number of multiplexed interferometers is small and the structure is complex

However, it does not consider the impact of the sensor array and some sensors in the network to be broken or destroyed.

[0013] In the low-coherence twisted Sagnac-like optical fiber deformation sensing device disclosed by the applicant in 2007 (Chinese Patent Publication No.: 101074867A), although the interferometer structure can theoretically solve the problem of anti-destruction, but because its structure is too complicated, In particular, the optical signal has too many paths, the intensity is weak, and the signal-to-noise ratio is low, which is not conducive to the deployment and use in actual measurement

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