Unbalanced polarization maintaining fiber dual-interferometer temperature strain simultaneous measurement device and method

Abstract

The present invention provides an unbalanced polarization maintaining fiber dual-interferometer temperature strain simultaneous measurement device and method. A polarization-maintaining fiber coupler,a phase modulator, a polarization-maintaining fiber and a polarization-maintaining fiber reflector form an unbalanced polarization-maintaining fiber interferometer. A light source injects light intoa fast axis and a slow axis through a polarizer at the same time for transmission, coaxial transmission signal interference is achieved in the interferometer, interference signals are detected by a polarization beam splitting difference detection device formed by a polarization-maintaining circulator, a polarization beam splitter and a photoelectric detector, and finally, a signal collection and demodulation and record device processes the interference signals. Parameters of the fast axis and the slow axis of the polarization maintaining fiber are different to allow fast-axis signals and slow-axis signals to have different responses for the same temperature and the same strain, and an unbalanced interferometer structure is employed to construct an orthogonal response matrix and measure temperature response coefficients and strain response coefficients of two paths of interference signals to achieve simultaneous measurement of temperatures and strains. The unbalanced polarization maintaining fiber dual-interferometer temperature strain simultaneous measurement device and method solve the intersection sensitivity problem, the measurement result is accurate and stable, and the sensitivity is high.

Description

technical field [0001] The invention relates to an optical fiber sensing technology, in particular to an unbalanced polarization-maintaining optical fiber double interferometer temperature and strain simultaneous measurement device and method. Background technique [0002] With the rapid development of human society, various large-scale infrastructure facilities are constantly being constructed. In the structural safety guarantee of large-scale modern engineering structures, such as dams, skyscrapers and bridges, strain detection is an indispensable means. In many During the production, construction and maintenance of engineering structures, strain testing is required to ensure the quality of construction and operation. In addition, strain detection has very important applications in human activities such as seismic and crustal strain monitoring, oil well exploration, and marine environment detection, so various strain detection sensors emerge in endlessly. [0003] Compare...

AI Technical Summary

Problems solved by technology

[0010] However, for the most widely used fiber optic interferometer sensors, the method of setting the reference fiber optic measurement system and the use of integrated fiber optic strain and temperature sensors are mainly used to solve the temperature and strain cross-sensitivity problems of fiber optic interferometer sensors, but these two methods The disadvantages are also obvious

Therefore, there is no simple, effective and universally applicable method to solve the problem of temperature and strain cross-sensitivity of fiber optic interferometer sensors in the existing patented technology

Images