Abstract: The present invention is related to a method for determining distributed temperature variation of a few mode optical fiber comprising the steps of:—providing a few mode optical fiber;—enlighting a first end of said few mode optical fiber by means of a coherent light source;—determining the interference pattern of coherent light at a second end of the optical fiber;—selecting one maximum of intensity at the second end of the optical fiber by spatially filtering the enlighting at the first end of the optical fiber;—determining the path length of the trajectory of the selected maximum of intensity;—based upon the determined path length of the trajectory of the selected maximum of intensity, determining the temperature variation of the few mode optical fiber.

Abstract: The present invention is related to a method for determining distributed temperature variation of a few mode optical fibre comprising the steps of:—providing a few mode optical fibre;—enlighting a first end of said few mode optical fibre by means of a coherent light source;—determining the interference pattern of coherent light at a second end of the optical fibre;—selecting one maximum of intensity at the second end of the optical fibre by spatially filtering the enlighting at the first end of the optical fibre;—determining the path length of the trajectory of the selected maximum of intensity;—based upon the determined path length of the trajectory of the selected maximum of intensity, determining the temperature variation of the few mode optical fibre.

Abstract: A method for characterizing an optical link by its beat length, coupling length and polarization mode dispersion is disclosed. A pulsed signal is sent along said optical fiber link and the backscattered signal (being a POTDR signal) is measured after passing through a polarizer. The length of said optical fiber, the average power difference between two successive minima of said backscattered signal and the number of maxima per unit length are derived. In an iterative way a beat length interval and an interval for the polarization mode coupling parameter are determined until the length of said intervals is below a predetermined value, yielding a value for the beat length and the coupling length, and the polarization mode dispersion is calculated.

Abstract: A method for characterizing an optical link by its beat length, coupling length and polarization mode dispersion is disclosed. A pulsed signal is sent along said optical fiber link and the backscattered signal (being a POTDR signal) is measured after passing through a polarizer. The length of said optical fiber, the average power difference between two successive minima of said backscattered signal and the number of maxima per unit length are derived. In an iterative way a beat length interval and an interval for the polarization mode coupling parameter are determined until the length of said intervals is below a predetermined value, yielding a value for the beat length and the coupling length, and the polarization mode dispersion is calculated.