Wavelength modulation optical fiber acoustic sensor

Abstract

The invention provides a wavelength modulation optical fiber acoustic sensor which comprises a laser, an optical fiber FP (fabry-perot) interference cavity acoustic probe, a first photoelectric detector and a signal processing and controlling module, wherein a laser power supply provides driving current to the laser, and the wavelength of the laser can be continuously adjusted; laser emitted by the laser is reflected after entering the optical fiber FP interference cavity acoustic probe, and an optical signal is output; the first photoelectric detector is used for receiving the optical signal output by the optical fiber FP interference cavity acoustic probe; the signal processing and controlling module is used for determining the optimal working wavelength of the wavelength modulation optical fiber acoustic sensor according to a direct current component of the output signal of the first photoelectric detector, and regulating the output wavelength of the laser to be the optimal working wavelength of the wavelength modulation optical fiber acoustic sensor by controlling the laser power supply to apply a driving current value corresponding to the optimal working wavelength to the laser. When the wavelength modulation optical fiber acoustic sensor is used, the optimal working wavelength is automatically selected without manual operation and calibration, so that the wavelength modulation optical fiber acoustic sensor is convenient to use and high in environmental adaptability.

Description

technical field [0001] The invention relates to the technical field of optical fiber sensing, in particular to a wavelength modulation optical fiber acoustic sensor. Background technique [0002] The optical fiber FP cavity acoustic sensor is an acoustic wave detection device based on optical phase measurement. It has the advantages of simple structure, low power consumption, high sensitivity, wide audio frequency response range, no electromagnetic radiation, anti-electromagnetic interference, and good compatibility with optical fiber communication networks. , is a new generation of acoustic detection devices following the electret acoustic sensor, suitable for forming a distributed optical fiber acoustic detection network system with good concealment, and has broad application prospects in industry, military, medical, environmental protection and other fields. For example, it can be used for environmental noise monitoring, pipeline gas leakage monitoring, ultrasonic mechani...

AI Technical Summary

Problems solved by technology

These two structures have a certain effect on improving the temperature stability of the fiber optic FP cavity acoustic sensor, but they still cannot eradicate the problem of sensor response characteristics drifting with temperature

Therefore, it is necessary to adopt more effective methods and technologies to completely eliminate the shortcomings of poor temperature stability of fiber optic FP cavity acoustic sensors

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