Kramers-Kronig detection with the Brillouin-amplified virtual carrier.

We proposed a novel scheme for realizing Kramers-Kronig detection by utilizing the narrow-band and high-gain characteristic of stimulated Brillouin scattering. At the receiver, the weak virtual carrier located at the edge of the signal spectrum is Brillouin amplified by the output of a slave laser, which is injection locked by a weak pump seed provided by the transmitter. More than a 2.7-dB optical signal-to-noise ratio sensitivity improvement is experimentally obtained compared with the traditional virtual carrier assisted scheme after an 80-km transmission. The effective number of bits requirement and the performance gain in the nonlinear transmission are both analyzed by the simulation.