Fiber laser static strain beat frequency demodulation system based on SSB frequency sweep modulation

Abstract

The invention discloses a fiber laser static strain beat frequency demodulation system based on SSB frequency sweep modulation, which includes a pump source, a coupler, a first wavelength division multiplexer, a second wavelength division multiplexer, a first Polarization controller, second polarization controller, fiber laser for sensing, fiber laser for reference, first isolator, second isolator, first beam combiner, second beam combiner, first broadband photodetector , second broadband photodetector, control processor, narrow linewidth laser light source, third isolator, third polarization controller, third beam combiner, suppressed carrier single sideband modulator, fourth beam combiner, Frequency sweep signal generator, phase modulator, radio frequency signal generator, frequency stabilization source and photodetector. The invention realizes the high-precision static strain measurement of the fiber laser, and solves the problems that the existing fiber laser demodulation technology cannot realize the high-precision static strain measurement, and the influence of the non-linearity of tunable laser frequency sweep on the demodulation precision.

Description

technical field [0001] The invention relates to the technical field of optical fiber sensing, in particular to an optical fiber laser static strain beat frequency demodulation system based on SSB frequency sweep modulation. Background technique [0002] With the continuous development of optoelectronic technology, since the late 1990s, a new generation of sensors using distributed feedback fiber lasers (DFB-FL) and distributed reflection fiber lasers (DBR-FL) as sensing elements have emerged. A research hotspot in the field of sensing in recent years. In addition to the advantages of ordinary FBG sensors such as simple structure, anti-electromagnetic interference, small size, and easy construction of sensor networks through wavelength division multiplexing, it also has unique advantages such as single frequency, narrow linewidth, high power, and ultra-low noise. Combined with high-resolution wavelength demodulation technology, it can achieve ultra-high sensitivity signal de...

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Problems solved by technology

[0007] In view of this, the main purpose of the present invention is to provide a fiber laser static strain beat frequency demodulation system based on SSB frequency sweep modulation, so as to realize high-precision static strain measurement of fiber lasers and solve the problem of existing fiber laser demodulation technology. Unable to achieve high-precision static strain measurement, tunable laser frequency sweeping non-linear impact on demodulation accuracy and other issues, and at the same time solve the impact of narrow linewidth laser source wavelength or frequency drift on demodulation accuracy

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