The optical communication technology features low cost, wide band, low loss, and anti-electromagnetic interference performance. By combining the optical communication technology with the radio millimeter wave communication system, the Millimeter Wave Radio over Fiber (MM-RoF ) system boasts a lot of advantages, including wide band, small size, light weight, low cost, low loss, and resistance of electromagnetic interference as well as high transmission quality. The MM-RoF technology solves the problems faced by traditional microwave transmission system at the millimeter wave band, namely, high loss and inability to resist interference efficiently. Meanwhile, it puts an end to the bottleneck of millimeter wave electronic devices and thus is deemed as with great potentials. The MM-ROF technology that supports multiple formats and services signifies one of the significant trends for future development of the MM-RoF system.