High resolution polarization low-coherence interferometry pressure measurement device and method

Abstract

The invention discloses a high resolution polarization low-coherence interferometry pressure measurement device and method. The device comprises a broadband light source (1), an optical fiber coupler (2), an optical fiber Fabry-Perot sensor (3), a collimating lens (4), a polarizer (5), a birefringent optical wedge with a space dip angle (6), an analyzer (7), an area-array camera (8) and a signal processing unit (9), an interference demodulator is formed by the collimating lens (4), the polarizer (5), the birefringent optical wedge with the space dip angle (6), the analyzer (7) and the area-array camera (8); an optical lever effectively adopts birefrigent effect, and different degrees of zoom in horizontal and vertical direction of the low-coherence interference fringe is realized through a designed two-dimensional space wedge angle of the birefringent optical wedge with the space dip angle; compared with the prior art, the space wedge angle of the birefringent optical wedge in the vertical direction is introduced, the signal is received by the area-array camera, and the pressure demodulation with large measuring range and high resolution can be realized.

Description

technical field [0001] The invention belongs to the field of optical fiber sensing, in particular to a high-resolution polarization low-coherence interference pressure measurement device and method based on an area array camera. Background technique [0002] In 1983, Al-Chalabi et al. (S.A.Al-Chalabi, B.Culshaw, D.E.N.Davies, Partially coherent sources in interferometric sensors, First International Conference on Optical Fiber Sensors, 1983: 26-28) first proposed a demodulation method based on low coherence interference in the field of optical fiber sensing. Demodulation interferometers based on low-coherence interference technology are mainly divided into two types: mechanical scanning type and electronic scanning type. The ultimate purpose of these two types of interferometers is to generate a series of optical path differences on the time axis or space axis. When a certain optical path difference generated by the demodulation interferometer matches the optical path differ...

AI Technical Summary

Problems solved by technology

The existing electronic scanning polarized low-coherence interference demodulation system uses a linear array photodetector array (such as a linear array CCD) to collect low-coherence interference fringes, and the demodulation method is generally based on one-dimensional low-coherence interference fringes. When measuring the pressure parameters with the microcavity length of the optical fiber Fapauer pressure sensor, its measurement range and measurement resolution are limited by the size and number of detector pixels, and it is usually necessary to make a trade-off between the two important indicators of measurement range and measurement resolution. It is difficult to achieve the two important indicators of large range and high resolution at the same time, which limits the application range of polarization-type low-coherence interferometric demodulation systems

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