With the advent of the 5th generation (5G) wireless systems, the development of mobile communication networks with large capacity, high frequency, and multi-service access is confronted with enormous challenges. In the 5G network, since the high-frequency signals are adopted, the coverage of a base station is greatly reduced and the number of base stations to be deployed is dramatically increased. Thus, the base stations tend to be miniaturized, densified, and passive for a large total coverage range together with lower overall costs and power consumption. The power-over-fiber (PoF) technique applied to radio-over-fiber (RoF) systems provides a solution to a new generation of distributed micro base stations. This technique, by transmitting the radio-frequency signals and power light to the base stations via optical fibers, achieves the power supply for the base stations and the emission of the wireless broadband signals with antennas. In this paper, we introduced the recent research progress of the PoF for RoF systems and analyzed its development trend by summarizing the features of typical schemes.