Long-Reach Multicast High Split-Ratio Wired and Wireless WDM-PON Using SOA for Remote Upconversion

We propose and experimentally demonstrate a cost-efficient hybrid gigabit wired and wireless long-reach and high split-ratio optical access network based on remote upconversion at the local exchange (LE). The scheme can deliver 40-GHz millimeter-wave wireless services supporting wavelength multicasting over 125-km standard single-mode fiber. A semiconductor optical amplifier (SOA) is used as the multiwavelength broadband optical upconverter and optical power amplifier inside the LE, and a high split-ratio of 512 can be supported. Wavelength multicasting can also be realized with conversion efficiency variation of within 1 dB over 15-nm wavelength range. The SOA has a gain with low polarization dependency and is able to realize multiwavelength operation based on four-wave-mixing for signal upconversion. Results show that the optical millimeter-wave signal distortion due to fiber chromatic dispersion can be significantly mitigated by using the proposed scheme. Expensive RF components are not required at the LE for signal upconversion because the SOA requires only dc bias. The polarization states of the input signals can be controlled at the head-end office; hence, polarization control in the LE may not be required. Error-free transmission for the wired signal was achieved and a power penalty of 2.3 dB was measured after 125-km transmission.