Dispersion and loss spectrum auto-correction distributed optical fiber raman temperature sensor

摘要

A dispersion and loss spectrum auto-correction distributed optical fiber Raman temperature sensor has a dual fiber pulsed laser module with dual Raman wavelength shifts. The laser module is composed of a power supply (11), an electronic switch (12), a primary laser (13) and a secondary laser (14), a first combiner (15), a bidirectional coupler (16), a multimode fiber (17), an integrated optical fiber wavelength division multiplexer (18), a second combiner (19), a direct detection system (20), a signal collection and processing system (21) and a display (22). The sensor uses two light sources that have two Raman wavelength shifts, wherein the central wavelength of backward anti-Stokes Raman scattering peak of the primary light source coincides with that of the backward Stokes scattering peak center wavelength of the secondary light source, and the time domain reflection signal of the one-way optical fiber Rayleigh scattering is deducted. Based on the optical fiber Raman scattering temperature measurement principle, the dispersion and loss spectrum auto-correction method and the optical time domain reflection principle, the optical fiber dispersion and the loss spectrum can be self-corrected, and the random power loss caused by bending and stretching in installation can also be auto-corrected.

主权项

1. A dispersion and loss spectrum auto-correction distributed optical fiber Raman temperature sensor, comprising:
a dual fiber pulsed laser module having dual Raman shift wavelengths, the laser module including a power supply, an electronic switch, a primary laser having a primary laser wavelength, and a secondary laser having a secondary laser wavelength; a first combiner; a bidirectional coupler; a multimode optical fiber; an integrated optical fiber wavelength division multiplexer; a second combiner; a direct detection system; a signal collection and processing system; and a display; wherein output terminals of the primary laser and the secondary laser are connected with an input terminal of the first combiner, an output terminal of the first combiner is connected with an input terminal of the bidirectional coupler, and an output terminal of the bidirectional coupler is connected with an input terminal of the multimode optical fiber; wherein backward Rayleigh scattering and Raman scattering echoes of the multimode optical fiber enter an input terminal of the integrated optical fiber wavelength division multiplexer via the bidirectional coupler, the integrated optical fiber wavelength division multiplexer having three output ports, the first output port being an output port for a central wavelength of Raman scattering peak, the central wavelength of Raman scattering peak including an anti-Stokes Raman scattering wave of the primary laser and a Stokes Raman scattering wave of the secondary laser within the same waveband, the second output port being an output port for an optical fiber backward Rayleigh scattering wave of the primary laser wavelength, and the third output port being an output port for the optical fiber backward Rayleigh scattering wave of the secondary laser wavelength; wherein the first output port of the integrated optical fiber wavelength division multiplexer is connected with an input terminal of the direct detection system, the second and third output ports of the integrated optical fiber wavelength division multiplexer are connected with two input terminals of the second combiner, an output terminal of the second combiner is connected with another input terminal of the direct detection system, an output terminal of the direct detection system is connected with an input terminal of the signal collection and processing system, and an output terminal of the signal collection and processing system is connected with the display.