Phase modulation and demodulation device based on fiber grating hydrophone array

Abstract

The invention discloses a phase modulation and demodulation device based on a fiber grating hydrophone array. A fiber grating is used as a component of a hydrophone, and a reflection phase modulator with a Faraday rotating mirror is adopted, which makes the structure simpler and reduces the cost. Meanwhile, a PI / 2 phase modulation method is adopted, two orthogonal signals can be directly separatedby sampling, and there is no need for general reference signal mixing and filtering. Thus, the complexity of the algorithm is simplified, the phase noise is reduced, and the system is more applicable.

Description

technical field [0001] The invention belongs to the technical field of hydrophone signal demodulation, and in particular relates to a phase modulation and demodulation device based on a fiber grating hydrophone array. Background technique [0002] Sound waves are the only form of energy that can travel long distances in the ocean, and hydrophones are the basic devices for detecting sound waves in the ocean. Optical fiber hydrophones have the characteristics of high sensitivity, strong anti-electromagnetic interference, and resistance to harsh underwater environments. With the development of marine science, large-scale and miniaturization have become an important direction for the development of optical fiber hydrophone arrays. However, with the deepening of the application, the traditional optical fiber hydrophone array has shown its limitations, mainly in the complex structure of the traditional hydrophone array, the small detectable dynamic range, and the complicated demod...

AI Technical Summary

Problems solved by technology

However, the structure of the patented technical solution is relatively complicated, the reference signal is introduced, and the demodulation algorithm needs to be mixed and filtered, which increases the phase noise and increases the complexity of the demodulation algorithm

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