Photonic access network architecture

A photonic access network architecture is proposed that can create the large capacity and extremely flexible network needed to offer B-ISDN (broadband integrated services digital network) services economically. The networks are characterized by increased management flexibility and line capacity. Line capacity of over 100 Gb/s is possible with a single-mode fiber. This architecture uses WDM (wavelength division multiplexing), FDM (frequency division multiplexing), and optical switching techniques to keep pace with service and demand growth. A wavelength division optical switch is proposed that permits the establishment of this architecture. The switch is composed of Mach-Zehnder interferometers with a thermooptic phase shifter. By using LSI microfabrication technology, a switch that supports eight wavelength signals can be constructed on one silicon wafer. >