The recent explosive growth in communications has been brought about by fiber optic and wireless communications technologies. These two technologies have merged to create an interdisciplinary area called microwave photonics, including RF optical links, oscillators, and radar. The research in the Optoelectronic Device Group at ShanghaiTech University is focused on the development of optoelectronic components and technologies that enable new applications and advances in microwave photonic systems. One of the key devices for the signal generation in microwave photonic systems is the high-speed, high power photodiode. Our work includes the development of state-of-the-art Silicon based, GaAs based, InP based high-speed, high power photodetectors and arrays.