The invention discloses a
fiber Raman
frequency shifter double-
wavelength pulse coding
light source self-correcting distribution type
fiber Raman temperature sensor which comprises a pulse coding
fiber laser driving power supply, a pulse coding
fiber laser, a fiber shunt, a fiber Raman
frequency shifter, two fiber
wavelength division multiplexers, two fiber switches, a sensing fiber, a photoelectric receiving module, a
digital signal processor and an industrial
personal computer, wherein the sensor obtains a Raman relevant double-
wavelength light source by the fiber Raman
frequency shifter with a pulse coding
fiber laser, bend because of fibers and optical cables and nonlinear loss caused by pressed stretching when a temperature measuring
optical fiber cable is used on site are subjected to
self correction. Measurement errors caused by deviation from
linearity when a Stokes Raman reference channel demodulates an anti-Stokes Raman
signal channel in the temperature measuring
system are overcome. The fiber Raman frequency shifter double-wavelength pulse coding
light source self-correcting distribution type fiber Raman temperature sensor has the advantages of low cost, long service life, simple structure, good
signal to
noise ratio and good reliability, and is suitable for monitoring
petrochemical pipelines, tunnels and large
civil engineering within the very long range of 80 kilometers.