Abstract: 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 (?f) 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 (?f+?f) 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.

Abstract: 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 (?f) 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 (?f+?f) 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.

Abstract: System and method of distributed sensing based on Brillouin stimulated scattering on optical fiber (3), consisting of separating the two signals of which the probe signal is composed and obtaining the difference between the stimulated amplification band (8) and the attenuation band (9), or vice-versa. In this way a signal is obtained with greater amplitude than in the case of detection being performed with a single band. Thus the signal-to-noise ratio is improved in the sensor signal, dynamic range and the range is increased and the uncertainty of the measurement is decreased. It also eliminates the common noise present in the two bands of the probe signal and, in the case of using a balanced detector in detection, it improves the saturation characteristics of the detector, being able to achieve much larger signal amplitudes than in the conventional case.

Abstract: System and method of distributed sensing based on Brillouin stimulated scattering on optical fiber (3), consisting of separating the two signals of which the probe signal is composed and obtaining the difference between the stimulated amplification band (8) and the attenuation band (9), or vice-versa. In this way a signal is obtained with greater amplitude than in the case of detection being performed with a single band. Thus the signal-to-noise ratio is improved in the sensor signal, dynamic range and the range is increased and the uncertainty of the measurement is decreased. It also eliminates the common noise present in the two bands of the probe signal and, in the case of using a balanced detector in detection, it improves the saturation characteristics of the detector, being able to achieve much larger signal amplitudes than in the conventional case.

Abstract: The present disclosure is based on distributed amplification based on the Raman Effect, consisting of one or more pump lasers (5) at various wavelengths combined with a variable number of fiber optic reflectors (6). These elements induce in the fiber optic sensor (4) or measurement object the necessary conditions for the propagation of the sensor or measurement equipment signals in virtual transparency mode, improving the signal-to-noise ratio in the sensor and measurement equipment signal, improving the dynamic range and increasing the range of the sensor or measurement equipment by up to 250 km.

Abstract: The present disclosure is based on distributed amplification based on the Raman Effect, consisting of one or more pump lasers (5) at various wavelengths combined with a variable number of fibre optic reflectors (6). These elements induce in the fibre optic sensor (4) or measurement object the necessary conditions for the propagation of the sensor or measurement equipment signals in virtual transparency mode, improving the signal-to-noise ratio in the sensor and measurement equipment signal, improving the dynamic range and increasing the range of the sensor or measurement equipment by up to 250 km.