A method and a system for interrogating an optical fiber includes a probe signal that has a first frequency comb at a first repetition rate (Δf) injected into the optical fiber. A backscattering signal that includes the probe signal convolved with an impulse response of the optical fiber in reflection which is sensitive to at least one parameter being measured from the optical fiber is gathered. The backscattering signal is beaten with a local oscillator signal to generate a beating signal, the local oscillator signal including a second frequency comb at a second repetition rate that is offset from the first repetition rate (Δf+δf) and being mutually coherent with the first frequency comb. The resulting beating signal is analysed to thereby determine the at least one parameter being measured from the optical fiber.

Aspects of the present disclosure describe systems, methods, and structures for distributed temperature sensing that employ joint wavelet denoising to achieve desirable signal-to-noise ratio(s) over extended sensor fiber distances.

Aspects of the present disclosure describe systems, methods, and structures for distributed temperature sensing that employ joint wavelet denoising to achieve desirable signal-to-noise ratio(s) over extended sensor fiber distances.

A temperature measuring method of distributed multi-section optical fibers, a system and a storage medium are provided. The method includes the following steps: obtaining data of original stokes and anti-stokes signals in a while optical fiber; distinguishing segments of a high-temperature and ordinary optical fibers according to a discontinuous point of signal data; performing interpolation calculation on the data of the segments of the high-temperature and ordinary optical fibers, respectively, according to their respective corresponding group refractive indexes, to align the data of the stokes and anti-stokes signals; according to the data of the aligned stokes and anti-stokes signals, respectively calculating temperature data of the high-temperature and ordinary optical fibers, respectively obtaining calibration parameters of the high-temperature and ordinary optical fibers; generating a final temperature according to temperature data of the high-temperature and ordinary optical fibers and their corresponding calibration parameters.

In some examples, optical fiber identification and distance measurement may include utilizing a reflectometer and optical fiber connection device that includes a Rayleigh wavelength pass filter to pass, in one direction, an optical reflectometer signal to an optical fiber. The reflectometer and optical fiber connection device may include a Raman wavelength pass filter to filter out, in another direction, Rayleigh backscattering from the optical reflectometer signal. Further, the Raman wavelength pass filter may pass, in the another direction, a Raman Anti-Stokes signal from the optical fiber.

A sensor and a method of manufacture of a sensor. The sensor includes a body having a groove therein, a first optical fiber and second optical fiber disposed in the groove, and a first layer and second layer bonded in the groove. The groove is formed in the body of the sensor. The first optical fiber is deposited in the groove. The first layer is bonded in the groove to form a first chamber in which the first optical fiber is disposed. The second optical fiber is disposed in the groove. The second layer is bonded in the groove to form a second chamber in which the second optical fiber is disposed.

A sensor and a method of manufacture of a sensor. The sensor includes a body having a groove therein, a first optical fiber and second optical fiber disposed in the groove, and a first layer and second layer bonded in the groove. The groove is formed in the body of the sensor. The first optical fiber is deposited in the groove. The first layer is bonded in the groove to form a first chamber in which the first optical fiber is disposed. The second optical fiber is disposed in the groove. The second layer is bonded in the groove to form a second chamber in which the second optical fiber is disposed.

A temperature demodulation method oriented toward a distributed fiber Raman temperature sensing system, the method comprising the following steps: step 1 of constructing a high-precision temperature detection device oriented towards a distributed fiber Raman sensing system; step 2 of performing signal processing with respect to Stokes light and anti-Stokes light at a calibration stage; step 3 of performing signal processing with respect to Stokes light and the anti-Stokes light at a measurement stage; and step 4 of obtaining a high-precision temperature demodulation technique oriented toward the distributed fiber Raman sensor. The method is used to effectively resolve the issue of low temperature measuring accuracy caused by Rayleigh crosstalk in existing distributed fiber Raman temperature measurement systems, and temperature measurement accuracy thereof is expected to fall within ±0.1° C. The method is applicable to distributed fiber Raman temperature measurement systems.

A temperature demodulation method oriented toward a distributed fiber Raman temperature sensing system, the method comprising the following steps: step 1 of constructing a high-precision temperature detection device oriented towards a distributed fiber Raman sensing system; step 2 of performing signal processing with respect to Stokes light and anti-Stokes light at a calibration stage; step 3 of performing signal processing with respect to Stokes light and the anti-Stokes light at a measurement stage; and step 4 of obtaining a high-precision temperature demodulation technique oriented toward the distributed fiber Raman sensor. The method is used to effectively resolve the issue of low temperature measuring accuracy caused by Rayleigh crosstalk in existing distributed fiber Raman temperature measurement systems, and temperature measurement accuracy thereof is expected to fall within ±0.1° C. The method is applicable to distributed fiber Raman temperature measurement systems.

The disclosure concerns a device (101) for distributed sensing comprising: a pump generator (1) for generating an optical pump signal, a pump splitter (2) configured to split the pump signal in a number N of channels (3), each channel comprising an optical fiber (31) or a connector (32) arranged for connecting an optical fiber, a controller configured to control the pump splitter, an optical receiver (4) for receiving a backscattered signal from the optical fiber or from the connector of each channel. The pump splitter comprises a gating system comprising a gate (21) for each channel among the N channels. Each gate is associated to a given channel and has an open state allowing the pump signal to go from the pump generator to the optical fiber or the connector of the associated channel, and a closed state for which the pump signal cannot go from the pump generator to the optical fiber or the connector of the associated channel.