An array of photonic filtering advantages: arrayed-waveguide-grating multi/demultiplexers for photonic networks

The author introduces the principles, fabrication techniques, and recent progress of planar-type arrayed-waveguide-grating (AWG) multi/demultiplexers, which have been developed for wavelength division multiplexing (WDM)-based photonic networks. The AWG has already been used in point-to-point WDM systems and is a key component in the construction of flexible and large-capacity WDM networks. This is because, compared with conventional filters consisting of thin-film interference filters and micro-optics, the AWG offers the advantages of low loss, high port counts, and mass productivity. Further progress on the AWG is expected to contribute greatly to the construction of future photonic networks including optical add/drop multiplexing systems and optical crossconnect systems.