Experimental demonstration of plastic optical fibre-based digitised radio over fibre downlink

Fibre links that are a few hundreds of metres long are needed for in-building networks. However, the transmission of radio-frequency (RF) signals through low-cost, easily installable plastic optical fibre (POF) is severely limited by their bandwidth-length products. Digitised radio over fibre (DROF) converts the RF signal into a baseband signal through bandpass sampling prior to its transmission, thereby reducing the fibre bandwidth required for the RF signal´s transmission. For the first time, a POF-based DROF link relying on the Ethernet protocol is proposed and the initial experimental results for a link that employs a 143 m long step-index POF and uncoded RF modulation are presented. A 5 GHz RF signal through the POF is transmitted. The same method can be employed for higher RF carriers as well. The RF bit rate was ~30% of the protocol-dependent DROF bit rate.