Abstract

A hierarchical all-optical network (AON) test-bed using two levels of passive wavelength routing is being fielded in the Boston metropolitan area (Fig. 1). Twenty channels are carried on frequencies spaced by 50 GHz. Channels are accessed through optical terminals (OTs) offering 1.244 and 2.488 Gbps circuit-switched "A" service or scheduled simultaneous TDM/FDM "B" service with an aggregate rate per channel of 1.244 Gbps. The B-service allows simultaneous independently-optically-routed connections of differing bit rates to share network resources such as terminal equipment and wavelengths by dividing transmissions into 128 independently-allocated 1.953 (is time slots. Each time slot can use a different wavelength. DBR-laser transmitters tunable in <25 ns are used in both services. Tunable receivers using fiber Fabry-Perot filters are used in the "A" service and DBR-laser polarization diversity heterodyne receivers are used for fast tuning and frequency sharing in the B-service. Wavelength-routed point-to-point and multicast services among any set of optical terminals are demonstrated. No optical/electronic conversions occur within the data path; passive wavelength routing using polarization-independent silica-on-silicon (SOS) phased-array optical waveguide technology is implemented in both local and metropolitan domains. A 1310 nm overlay "C" service network enables AON functions such as messaging, timing distribution and scheduling.

© 1995 Optical Society of America