A Research on Bi-directional Double Clad Optical Fiber for 5G Communication with Multiband Radio Signal and Power for Disaster Management in Remote Units

The power over fiber (PoF) scheme delivers simultaneous multiband data and feed power transmission via a double-clad fiber (DCF) for bidirectional radio over fiber (RoF) system. The 5G technology demands cell splitting resulting in an increasing number of remote antenna units (RAU). The RAU is conventionally powered by public power lines. The PoF system is the potential candidate to deliver the electrical power required to drive the RAU during the power outage due to natural calamities and disasters. The PoF system may ensure uninterrupted communication during the debacle. In the proposed scheme, the multiband data signals are generated and transmitted through the single-mode (SM) core of the DCF, whereas feed power from a high-power laser diode (HPLD) is transmitted through the inner cladding for which the core-effective area is larger than the SM core. To increase the electric power conversion efficiency, we use six customized photovoltaic converters (PVC) by introducing the back surface reflector beneath the active photovoltaic layer resulting in improved conversion efficiency of 68% at 858 nm operation wavelength. The power transmission loss can be reduced by using more PVC as it reduces the feed power leakage. As a result, the PoF system yields the power delivery of 12.33 W, sufficient to drive an RAU. The complexity of the system is reduced by using multiband signal over a single DCF and carrier reuse for uplink transmission enabling LD-free RAU. This work helps design the power delivery for the RoF system with DCF and achieve a good transmission performance with negligible power penalty.