Semiconductor optical amplifiers for digital and analog communication

Summary form only given. Semiconductor optical amplifiers (SOAs) are entering the fiber-optic domain, not as an alternative for the erbium-doped fiber amplifier, but as an enabling technology in different application areas. SOA technology offers low cost, compact devices, with a low power consumption. In addition, fast switching and operation at wavelengths outside of the 1.55-/spl mu/m band are possible. These advantages open the way towards the use of optical amplifiers in new as well as in existing applications. Applications under consideration for SOAs are short- and mid-distance digital communication systems, for instance local area, ring and/or access networks. In such systems, amplifiers are necessary to compensate for the losses due to signal distribution and multiplexing, in addition to fiber losses. Due to their high on-off ratios combined with fast switching characteristics, SOAs can also be used as signal switching elements, contributing greatly to the functionality of these networks. Looking further ahead, SOA technology can be applied to implement all-optical signal processing functions, such as add-drop multiplexing and wavelength conversion in wavelength-division multiplexing (WDM) systems. In the field of analog community antenna television communications, SOAs are also gaining ground.