Abstract: A method of sensing including the steps of, (a) acquiring measurement values using a distributed optical fibre sensor; (b) arranging the measurement values in a matrix having at least two dimensions; (c) transforming each measurement value in the matrix to a corresponding pixel value on a predefined scale of pixel values and forming an image with pixels having the corresponding pixel values, wherein each pixel in the image is positioned at a position in the image corresponding to the position of the measurement value in the matrix; (d) processing the image using an image processing algorithm so as to reduce noise in the image to provide processed image; (e) transforming each pixel value of pixels in the processed image to values to provide measurement values with reduced noise.

Abstract: This invention relates to a system and method to determine the distributed birefringence profile along an optical fibre. Birefringence manifests as different refractive indices for two orthogonal states of polarization of the light propagating in the optical fibre. The technique is based on the correlation among sets of measurements acquired using phase-sensitive optical time-domain reflectometry (?OTDR), launching light into the fibre with multiple states of polarization. The correlation between the measurements performed while sweeping the laser frequency gives a resonance (correlation) peak at a frequency detuning that is proportional to the refractive index difference between the two orthogonal polarizations. This enables measurements of the local value of the phase birefringence at any position along the optical fibre, so that longitudinal fluctuations of its value can be evaluated.

Abstract: System and methods for producing a plurality of Sinc shaped pulses in the time domain include a light source for providing an input light signal having an input frequency, and at least one spectrum shaper for producing the plurality of Sinc shaped pulses from the input light signal. The spectrum shaper may include an amplitude modulator, at least one radio-frequency generator and a bias voltage generator.

Abstract: System and methods for producing a plurality of Sinc shaped pulses in the time domain include a light source for providing an input light signal having an input frequency, and at least one spectrum shaper for producing the plurality of Sinc shaped pulses from the input light signal. The spectrum shaper may include an amplitude modulator, at least one radio-frequency generator and a bias voltage generator.