In this paper, recent progress in millimeter-wave (MMW) photonic gigabit wireless communication is reviewed. This technique is attractive partly because the MMW signal can be easily distributed from central to base stations through the use of a low-loss optical fiber. This radio-over-fiber approach facilitates the transmission of MMW signals. An MMW photonic transmitter, comprised of high-power photodiodes with integrated antennas for MMW signal broadcasting, is needed for signal generation only over the last mile. The development of several different low-noise optical MMW sources and high-power photonic transmitters and photodiodes for optical MMW wireless links is summarized. The performance of photonic wireless links with extremely high data rates (>10 Gbit s–1) developed based on these key components and using different modulation schemes is also reviewed. Finally, some advanced commercially available products and the prospects of a future gigabit wireless communication era are discussed.
The team of researchers, led by UC Berkeley engineering professor Xiang Zhang, built a tiny optical device that uses graphene, a one-atom-thick layer of crystallized carbon, to switch light on and off. This switching ability is the fundamental characteristic of a network modulator, which controls the speed at which data packets are transmitted. The faster the data pulses are sent out, the greater the volume of information that can be sent. Graphene-based modulators could soon allow consumers to stream full-length, high-definition, 3-D movies onto a smartphone in a matter of seconds, the researchers said.
Scientists have demonstrated for the first time that atoms can be guided in a laser beam and possess the same properties as light guided in an optical communications fiber.
The researchers’ work has implications for future quantum devices that require smoothly-guided matter waves, such as atom interferometers which need to sensitively measure the earth’s gravitational field for geo-exploration. Their paper is published today in Nature Communications.