Phase-shifted-signal-modulation-based fiber interference type sending modulation and demodulation method and device

A signal modulation and optical fiber interference technology, which is applied in the field of optical fiber interference sensing modulation and demodulation, can solve problems such as slow calculation speed, phase detection technology is susceptible to interference, and high hardware system requirements, so as to improve real-time performance and anti-environmental interference The effect of strong ability and high signal-to-noise ratio

Active Publication Date: 2017-09-19
NANJING UNIV OF SCI & TECH
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Problems solved by technology

[0004] The purpose of the present invention is to provide a method and device for optical fiber interference sensing modulation and demodulation based on phase-shift signal modulation, which solves the problems that traditional phase detection technology is susceptible to interference, high hardware system requirements, and slow solution speed

Method used

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  • Phase-shifted-signal-modulation-based fiber interference type sending modulation and demodulation method and device
  • Phase-shifted-signal-modulation-based fiber interference type sending modulation and demodulation method and device

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Embodiment 1

[0049] Experimentally tested the vibration information of a certain optical fiber Michelson sensor at 100Hz. The length difference between the reference arm 6 and the signal arm 5 is 2.8m, the sampling time is 0.02s, the frequency of the modulated square wave is 1MHz, and the modulated pulse width in one cycle is is 28ns, the measurement device such as figure 1 As shown, the measurement steps are:

[0050] Step 1. Turn on the micro-vibration table 12, and the micro-vibration table performs sinusoidal regular vibration at 100 Hz. Turn on the laser light source 1, the light emitted by the laser light source 1 passes through the isolator 2 and the phase modulator 3 in sequence, the signal generator 8 generates a high-speed pulse signal with a frequency of 1 MHz, and provides π / 2 phase modulation to the phase modulator 3 to form a Phase-modulated laser beams;

[0051] Step 2. The phase-modulated laser beam passes through the coupler 4 and enters its reference arm 6 and signal ar...

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Abstract

The invention discloses a phase-shifted-signal-modulation-based fiber interference type sending modulation and demodulation method and device. The device is composed of a laser light source, an isolator, a phase modulator, a 2*2 type coupler, a reference arm, a signal arm, a Faraday polariscope, a signal generator, a photoelectric converter, a data acquisition module, a data processing module and a micro-vibration table. On the basis of high-speed pulse phase modulation on the laser light source, multi-path phase shift signal generation is realized at the output terminal of the fiber sensor; and with a demodulation method of a multi-path phase shift algorithm, vibration phase demodulation of the fiber sensor is realized. The modulation and demodulation method has advantages of simple light path, simple demodulation circuit, good real-time performance, high precision, wide dynamic range and strong anti-environmental interference ability.

Description

technical field [0001] The invention belongs to the technical field of optical fiber sensing, and in particular relates to an optical fiber interference type sensing modulation and demodulation method and device based on phase-shift signal modulation. Background technique [0002] With the ever-increasing demand for energy and the increasingly scarce resources such as oil and natural gas, people pay more and more attention to the research on key technologies for oil and gas field exploitation. The geophone is the core device in geophysical exploration. The conversion of ground mechanical motion into electrical signals plays an important role in oil exploration. The current traditional geophones have shortcomings such as small dynamic range, low sensitivity, and poor anti-interference ability, which restricts high-resolution seismic to a certain extent. The development of exploration technology. Compared with traditional detectors, optical fiber sensors have many advantages ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): G01D5/353G01H9/00
CPCG01D5/353G01H9/004
Inventor 朱日宏任仲杰王海林李建欣王晓烨
Owner NANJING UNIV OF SCI & TECH
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