Electroabsorption Modulator Frequency Down-Conversion for Uplink Radio-Over-Fiber

We propose a novel and cost-effective frequency down-conversion technique for millimeter-wave (mm-wave)-over-fiber uplinks using an electroabsorption modulator (EAM) at the base station. It is found that the distributed optical local oscillator light from a central station can be directly modulated by the data signal down-converted from mm-wave inside the EAM and reused as the uplink optical signal with proper filtering. It is also demonstrated that the uplink mm-wave can be down-converted to either an intermediate frequency or the baseband. We numerically validate the feasibility of such a scheme and experimentally demonstrate the error-free performance by a total 40 km of fiber delivery with 1-dB receiver power penalty.