Single-Sideband Modulation Based on an Injection-Locked DFB Laser in Radio-Over-Fiber Systems

We report an experimental demonstration of optical single-sideband (SSB) modulation in 60-GHz radio-over-fiber systems based on an injection-locked distributed-feedback (DFB) laser. Two heterodyning optical modes with 60-GHz spacing are injected into the DFB laser and one of them is used to lock the DFB laser. When the DFB laser is directly modulated, the modulation index of the locked mode is 15 dB larger than that of the unlocked one. The 2.5-Gb/s data transmission at 60 GHz is successfully achieved over 50-km standard single-mode fiber using the proposed SSB scheme.