A high-capacity photonic space-division switching system for broadband networks

A high-capacity (128-line) photonic space-division switching system prototype has been developed. All of the developments on polarization-independent LiNbO₃ matrix switches, semiconductor optical amplifiers for network loss compensation and three-dimensional optical interconnections for multi-stage switching networks combine to enlarge line capacity. The system is devised to provide both HDTV distribution services that require nonblocking connections and TV phone services that do not necessarily require these connections. It is confirmed that the system has been operating in providing 150 Mbps TV phone services and 600 Mbps HDTV distribution services with high stability. Thus, the system proves to be promising for STM broadband switching systems capable of providing high-speed continuous dense bit-stream services. The system, in concert with an ATM broadband switching system, could provide a full range of cost-effective broadband services from POTS (plain old telephone services) to HDTV