Cascade acoustic microstructure optical fiber long cycle grating interferometer

Abstract

The invention relates to a cascade acoustic microstructure optical fiber long cycle grating interferometer which comprises a light source, a 3dB coupler, a microstructure optical fiber, two three-dimensional regulation frames, a signal generator, a piezoelectric ceramic chip, an acoustic amplifier, an acoustic damper, a spectrum analyzer, a connecting single-mode optical fiber and a lead, and belongs to the technical field of optical fiber induction. A sine electric signal is generated through the signal generator, acts on the piezoelectric ceramic chip, is converted into an acoustic signal, amplified through the acoustic amplifier and laterally loaded to the microstructure optical fiber to form an acoustic long cycle optical fiber grating, and then a Mach-Zehnder interference effect is formed through a high reverse film; and an induction optical fiber is corroded to generate an evanescent field and is arranged in an environment to be measured. In addition, a functional material is filled into the cladding air hole of the microstructure optical fiber, so that an electric field, a magnetic filed and the like can be measured and the induction sensitivity is further improved. The cascade acoustic microstructure optical fiber long cycle grating interferometer has the advantages that the structure is simple, the tunability is good, the sensitivity is high, and refractive index, temperature, the electric field, the magnetic field, gas concentration and other parameters can be induced.

Description

technical field [0001] The invention belongs to the technical field of optical fiber sensing, in particular to an interferometer based on cascaded acoustic-induced microstructure optical fiber long-period gratings, which can be used for real-time monitoring and measurement of physical quantities such as temperature, electric field, magnetic field, and liquid refractive index. Background technique [0002] Fiber Bragg Grating is a new type of photonic device, which has a periodic refractive index distribution along the axis of the fiber, so that it can control the propagation behavior of light in the fiber. The period of LPFG is usually in the range of tens of microns to hundreds of microns, which can realize the coupling of energy from the core mode to the cladding mode propagating in the same direction. There are many ways to realize long-period fiber gratings, including excimer laser irradiation, carbon dioxide laser irradiation, femtosecond laser irradiation, applying per...

AI Technical Summary

Problems solved by technology

[0006] The purpose of the present invention is to solve the above problems of poor tuning ability, difficulty in obtaining interference effect and complex structure based on ordinary solidified cascaded long-period fiber grating interferometers, and to provide a cascaded, flexible and adjustable, high-sensitivity, easy-to-implement cascade Microstructure fiber long-period grating interferometer induced by joint acoustics

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