Apparatus and method for spatially resolved measurement of temperature and / or expansion means Brillouin scattering

Device for the spatially resolved measurement of temperature and / or expansion means Brillouin scattering, comprising at least one laser light source (1) capable of generating a laser radiation, an optical fiber used for the measurement (5) into which the laser radiation can be coupled in and out of the basis of Brillouin scattering generated Brillouin signals can be coupled, sensor means which can detect the out-coupled Brillouin signals evaluation means, which can determine from the detected Brillouin signals, the temperature and / or elongation at least portions of the optical fiber (5) in a spatially resolved, at least a polarization beam splitter (10, 11) of the extracted Brillouin signals into two components (12, 13) may be split with mutually different polarizations, and at least one optical coupler (16, 17) which can be added to mix the Brillouin signal, a laser radiation.