Ultrafast optical techniques for communication networks and signal processing

Wireless communications, for data services in particular, have witnessed an exponential growth, and wireless spectrum shortages necessitate increasingly sophisticated methods to use spectrum efficiently. The backhaul of nearly all wireless data networks is fiber-optic. Analog optical signal processing techniques, or microwave photonics, provides an ideal platform for processing wireless information before it is transported to data aggregation centers by fibers. It is in this context that we present recent advances in optical signal processing techniques for wireless radio frequency (RF) signals. Specifically, this chapter is devoted to the discussion of photonic architectures for wideband analog signal processing, including RF beamforming, co-channel interference cancellation, and physical layer security. Photonics offers the advantages not only of broadband operation, but reduced size, weight, and power, in addition to low transmission loss, rapid reconfigurability, and immunity to electromagnetic interference.