Brillouin scattering was discovered in 1922 by Louis Brillouin [1]. It is one of a number of characteristic scattering phenomena that occur when light interacts with solid, liquid or gaseous media and corresponds to the scattering of light from thermally-induced acoustical waves (propagating pressure/density waves) present in media at all temperatures. At normal light levels the amount of scattering is small. The characteristics of the scattering can offer interesting information about the properties of the medium (temperature, pressure) and form the basis for remote fibre sensor devices. With intense coherent laser light, the rate of scattering can become so great that the acoustic wave amplitudes increase and the scattered.
