CPC G01N 21/17 (2013.01) [G01J 5/0821 (2013.01); G01N 2021/1734 (2013.01)] | 7 Claims |
1. An optical fiber sensing system for temperature and salinity synchronous measurement, comprising a broad-spectrum light source, an optical fiber circulator, a coupler, a first interferometer, a second interferometer, a third interferometer and a spectrometer;
wherein the first interferometer is connected in series with the optical fiber circulator and the coupler in sequence; the coupler is respectively connected with the second interferometer, the third interferometer and the spectrometer; the second interferometer is connected in parallel with the third interferometer;
the first interferometer is insensitive to the temperature and the salinity; the second interferometer is sensitive to both the temperature and the salinity, and the third interferometer is only sensitive to the temperature;
light emitted by the broad-spectrum light source passes through the optical fiber circulator and enters the first interferometer; reflected light of the first interferometer passes through the optical fiber circulator and the coupler in sequence, and then enters the second interferometer and the third interferometer respectively; reflected light of the second interferometer and the third interferometer enters the spectrometer after passing through the coupler; and the temperature to be measured and the salinity to be measured are simultaneously obtained by performing a spectral analysis of the reflected light entering the spectrometer;
the spectral analysis of the reflected light entering the spectrometer comprises:
respectively obtaining interference spectra of the first interferometer, the second interferometer and the third interferometer based on the reflected light entering the spectrometer;
obtaining a first interference spectra envelope between the first interferometer and the second interferometer based on the interference spectrum of the first interferometer and the interference spectrum of the second interferometer; obtaining a second interference spectra envelope between the first interferometer and the third interferometer based on the interference spectrum of the first interferometer and the interference spectrum of the third interferometer; and
obtaining the temperature to be measured and the salinity to be measured based on the first interference spectra envelope and the second interference spectra envelope; and
obtaining the temperature and the salinity comprises:
obtaining a first translation amount of the first interference spectra envelope and a second translation amount of the second interference spectra envelope when the temperature and the salinity change; and
obtaining the temperature to be measured and the salinity to be measured based on the first translation amount and the second translation amount.
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