A Novel Approach to Realizing SSB Modulation With Optimum Optical Carrier to Sideband Ratio

Abstract

A novel approach to realizing single sideband (SSB) modulation with optical carrier to sideband ratio (OCSR) of 0 dB, which is optimum for maximizing the transmission performance of a radio-over-fiber system, is proposed and experimentally demonstrated based on a strong optical injection-locked distributed feedback (DFB) laser. Tunable OCSR with optimum value of 0 dB is achieved by tuning the injection ratio and the detuning frequency precisely. A simulation is carried out to confirm the optimum OCSR. Gain properties of the DFB laser under strong optical injection are also measured for the first time to our knowledge. Doubled frequency of the LO signal is obtained without any filter. The generated optical SSB signal of 20 GHz is transmitted over 60-km single-mode fiber experimentally; results show it is almost not affected by the fiber chromatic dispersion.