Full-Duplex WDM-Based RoF System Using All-Optical SSB Frequency Upconversion and Wavelength Re-Use Techniques

We have experimentally demonstrated a full-duplex wavelength division-multiplexing-based radio-over-fiber system using all-optical single-sideband (SSB) frequency upconversion and wavelength re-use techniques for broadband optical-wireless access networks. The optical SSB RF signal having the RF frequency of 62.5 GHz is generated by using this all-optical frequency upconverter that consists of an arrayed waveguide grating for optical demultiplexing and a semiconductor optical amplifier for wavelength conversion based on the cross-gain modulation effect. The receiver sensitivity at the bit error rate of is 11.5 and for downlink (including air transmission of 1.5 m) and uplink, respectively. The power penalties originating from the fiber chromatic dispersion are negligible after transmission over 25-km standard mode fibers (SMFs) for both downlink and uplink. For the IF wavelengths from 1530 to 1580 nm (covering -band), the variation of the receiver sensitivity is less than 2.5 dB.