Suppression of SBS-Induced RF Phase Noise in an RF-Photonic Link

In this paper, we examine and suppress the effects of stimulated Brillouin scattering on the phase noise of a 10 GHz signal transmitted over an RF-photonic link. We demonstrate the appearance of interference peaks in the RF phase noise of a microwave signal transmitted through a 10 km optical fiber link. We attribute these peaks to double Brillouin scattering using a reduced model. We determine that there are at least three optical noise sources at optical powers relevant to RF transmission: shot noise, Rayleigh scattering, and stimulated Brillouin scattering. Furthermore, we demonstrate the suppression of noise from both Rayleigh and Brillouin scattering using frequency modulation. We demonstrate further suppression of phase noise from Brillouin scattering using a concatenation of fibers with different Brillouin frequency shifts.