Types and Applications of Fiber-Optic Sensors Based on the Mandelstam - Brillouin Scattering Principle

The report presents a classification of fiber-optic sensors based on the Mandelstam - Brillouin scattering principle. The spectrum of backscattered light waves and a mathematical description of the carrier frequency shift of the scattered signal are given. The classified sensors can function in the time or frequency domain. Sensors of the first category assume the input of a probing signal either from one end of the optical fiber, or from both ends. The results of a comparative analysis of the technical characteristics of commercial systems operating on the principle of Mandelstam - Brillouin scattering are presented. It is noted that systems of the first group have the best metrological characteristics in terms of spatial resolution and measurement errors, but are inferior to the systems of the second group in terms of measurement range. The examples of application of the studied systems for monitoring engineering structures, temperature measurement, leak detection in pipelines and stresses in composite materials are analyzed.