
Passive optical LAN (POL) is a Layer-2 transport medium, built with passive optical network (PON) technology, which provides converged data, video, and voice services at gigabit speeds over a single strand of fiber to the user's location. These solutions make use of a number of passive optical components. Majority of these components including optical cables, optical couplers, optical power splitters, optical encoders, patch cords and pigtails, optical connectors, optical amplifiers, optical transceivers, fixed and variable optical attenuators, optical circulators, wavelength division multiplexers/de-multiplexers, and optical filters can now be found in use in FTTH applications and current data networks. These components also find use in applications such as fiber in the loop (FITL), interoffice, loop feeder, hybrid fiber-coaxial cable (HFC), synchronous digital hierarchy (SDH) systems and synchronous optical network (SONET).