PLC is the English abbreviation of Planar Lightwave Circuit, namely the planar optical waveguide. The optical passive device and traditional vertical difference, PLC devices are used by semiconductor fabrication, which can integrate the optical components with different functions into one chip. PLC is the basic technology of photoelectric device integration, modularization, miniaturization. The devices those are used PLC technology include: optical splitter, arrayed waveguide grating (AWG), variable optical attenuator (VOA), variable optical attenuation combiner (VMUX), reconfigurable optical add-drop multiplexer (ROADM) and so on.
