High speed photoreceiver over 100 GHz and its application

In wireless communications, the data traffic increases rapidly every year, as well as in fixed optical fiber communications, where the trend for data traffic is not saturated yet. In the next generation of advanced wireless communication services, a high data rate, high capacity, low latency, and low cost are desired. The large radio cover area for present macro-cell should be divided into plenty of small-cells in order to mitigate heavy data traffic in the one macro-cell [1]. Here, radio over fiber (RoF) is a promising technology for access networks such as mobile back-haul and front-haul in wireless communication. High data rate transmission through optical fibers should be introduced near end-user points and be converted to radio signals from simple antennas in small-cells. Here, a high speed photoreceiver is one of key components in RoF communications. On the other hand, power over fiber (PoF) technology, which provides electric power supply through optical fibers, is a compatible technology with a good affinity to RoF technology. The 90 to 110 GHz band is a very attractive frequency band, which involves not only low atmospheric attenuation [2] but also a wider bandwidth compared to that in the microwave region.