Accelerometer probe head and device based on phase shift grating fiber laser

Abstract

The invention discloses a phase shift grating fiber laser-based acceleration measuring detection head and device. The detection head is formed by two fiber gratings with real phase shifts or equivalent phase shifts which are connected in series through a gain fiber, under the condition of loading prestrain, the two fiber gratings are fixed on a support whose coefficient of thermal expansion is zero or can be negligible; and the plane where the first fiber grating is and the fiber direction are vertical to the plane where the second fiber grating is. The device includes a pumping semiconductor laser, a pumping light isolator, a variable optical attenuator, an optical detector, a frequency spectrograph and the detection head. The phase shift grating fiber laser-based acceleration measuring detection head and device provided by the invention can eliminate influence of grating periodic fluctuation on a measuring result due to a temperature change; increase the sensitivity of the measuring result; and lowers processing difficulty and manufacturing cost of the fiber gratings; and if the lasing frequency of one fiber grating is smaller than that of the other all the time, the frequencies of obtained two laser beat frequency signals can reflect the measured acceleration and direction at the same time.

Description

technical field [0001] The invention belongs to the technical field of optoelectronics, and relates to optical fiber communication, photoelectric sensing and photoelectric information processing. The present invention is an acceleration measurement device based on a phase-shift grating dual-wavelength fiber laser, in which one laser wavelength is fixed, and the other laser wavelength can be changed according to the magnitude and direction of the acceleration, so the beat frequency of the two wavelength lasers can be Reflect the magnitude and direction of acceleration. Background technique [0002] Sensors made of dual-wavelength fiber lasers have very important applications in photoelectric sensing, microwave signal generation, and photoelectric information processing. Sensors made of fiber grating lasers have received extensive attention in modern production technology because of their simple and compact structure, high measurement accuracy, and the ability to interconnect...

AI Technical Summary

Problems solved by technology

At present, there are many designs of acceleration measurement devices based on fiber lasers, but some of them have complex structures, and some have no temperature desensitization device or the temperature desensitization effect of the temperature desensitization device is not ideal.

For example, the design scheme proposed in the document "Rui Ma, et.al, Two-axis slim fiber laser vector hydrogen, IEEE Photonics Technology Letters, 23(6):335-337, 2011" has a complex structure and no temperature desensitization device , cannot eliminate the influence of temperature drift on the measurement results

Although the design in the literature "Tang Caijie et al., A Fiber Optic Accelerometer with Differential Double Grating Structure, Chinese Invention Patent, ZL: 201310712441. The device that fixes the fiber grating will still change in length due to temperature changes, which will cause the length of the grating to change and bring errors to the measurement results

Especially when the grating periods of the two gratings differ greatly, the error caused by this effect is greater

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