Crosstalk due to stimulated Brillouin scattering in monomode fibre

Interactions between two counterpropagating narrowband lightwaves (frequency difference=20 GHz, lambda =825 nm) in a monomode optical fibre can occur because of stimulated Brillouin scattering. Maximal signal gain of 10% is obtained for a pump power of 313 mu W. The interactions extend over 500 MHz with two resonant frequencies.