Flexible compensation of dispersion-induced power fading for multi-service RoF links based on a phase-coherent orthogonal lightwave generator.

A novel technique to simultaneously compensate dispersion-induced power fading for multi-service radio-over-fiber (RoF) links is proposed. At the central office (CO), a phase-coherent orthogonal lightwave generator (POLG) consisting of a polarization rotator (PR) and a single-driver Mach-Zehnder modulator (MZM) is used. By adjusting a polarization controller (PC) in the base station (BS), the phase difference between the orthogonal polarization carrier and two sidebands can be controlled, and the frequency response can be flexibly shifted for individual radio frequency (RF) service. We experimentally shift the destructive interference to the constructive interference at various frequencies for 25 km and 30 km fiber links. The performances of two services carrying 1 Gb/s on-off keying (OOK) data at 9 GHz and 16.6 GHz over a 30 km fiber in the proposed system show receiver sensitivity improvement of ∼12  dB at the bit error rate (BER) of 10(-3) compared with the conventional double sideband (DSB) modulation case.