Wavelength-interleaving technique to improve optical spectral efficiency in millimeter-wave WDM fiber-radio

In this paper we present a novel wavelength-interleaving scheme to increase the optical spectral efficiency in mm-wave WDM fiber-radio systems and demonstrate the feasibility of the proposed scheme via experiment and simulation. The technique employs wavelength interleaving in conjunction with OSSB+C modulation. A wavelength-interleaved optical add-drop multiplexer using fiber gratings and an optical circulator was realized to implement the technique, the feasibility of which was demonstrated via three interleaved WDM channels each transporting a 155 Mb/s BPSK signal at 36 GHz over a 20 km fiber link. Capacity analysis shows that the wavelength-interleaving technique increases the maximum number of channels by almost 75% after taking into account overall system performance and device limitation.