6-GHz Radio-Over-Fiber Upstream Transmission Using a Directly Modulated RSOA

We propose and demonstrate 40-km upstream transmission of a 2-Gb/s 6-GHz binary phase-shift keyed radio signal using a directly modulated reflective semiconductor optical amplifier (RSOA). A delay interferometer, acting as an optical equalizer, compensates for limited RSOA modulation bandwidth and simultaneously performs single sideband filtering to relieve dispersion-induced radio-frequency (RF) fading effect. Furthermore, extended transmission distance of up to 40 km is shown to be made possible by reduced Rayleigh backscattering-induced crosstalk.