Heterodyne-interference-type optical fiber hydrophone time division multiplexing array and demodulation method

Abstract

A heterodyne-interference-type optical fiber hydrophone time division multiplexing array and a demodulation method are disclosed. The optical fiber hydrophone time division multiplexing array comprises a narrow linewidth laser, a first coupler, a first acoustic-optical modulator, a second acoustic-optical modulator, a first optical fiber delay ring, a second coupler, a first circulator, a second circulator, a first photoelectric detector, a second photoelectric detector, a reference probe and a hydrophone sensing array. The sensing array adopts a parallel structure. Pulse light enters into each probe of the array through the delay ring in a time sharing mode so as to generate a sensing light signal. The reference probe is used for generating a reference light signal. The sensing light signal and the reference light signal are collected by the photoelectric detectors and then are converted into analog electronic signals. A signal demodulation module is used to carry out analog-to-digital conversion on the signals respectively. An arc tangent algorithm is used to resolve a submarine sound signal perceived by the sensing array.

Description

technical field [0001] The invention relates to the field of optical fiber hydrophones, in particular to a time-division multiplexing array and a demodulation method for a heterodyne interference optical fiber hydrophone. Background technique [0002] Optical fiber hydrophone is an important direction of modern sonar development. It converts the acoustic signal in water into the phase signal of interference light through the method of phase carrier, and obtains the phase information of light through demodulation algorithm, so as to obtain underwater acoustic information. According to the demodulation scheme, it is divided into active homodyne method, 3×3 coupler method, PGC method and heterodyne method. The selection and implementation method of the signal demodulation scheme is not only related to the detection sensitivity, dynamic range and other important index factors for fiber optic hydrophones, but also determines the optical path structure adopted by the array. [00...

AI Technical Summary

Problems solved by technology

[0006] In order to solve the problems of high-frequency detection of optical fiber hydrophones, "wet end" all-opticalization, consistency of optical fiber hydrophone probes, and time-division multiplexing array crosstalk of optical fiber hydrophones, the invention provides a heterodyne interferometric optical fiber hydrophone Time Division Multiplexing Array and Demodulation Algorithm

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