PHOTONIC SPACE-DIVISION SWITCHING TECHNOLOGIES FOR BROAD-BAND NETWORKS

The photonic Space-Division (SD) switching network is attractive for c onstructing flexible broadband networks. This paper first describes po ssible applications of the network. A broadband STM switching system, Digital Cross-connect System (DCS) and Video signal distribution switc h, especially for HDTV signals, are attractive near term applications. Recent activities on photonic SD switching network developments aimin g at these application are also reviewed. A 128 line prototype switchi ng system has been developed. This system utilizes LiNbO3 photonic swi tch matrices, semiconductor traveling wave amplifiers (TWAs) and three dimensional optical interconnections for multi stage switching networ ks. It is confirmed that the system has been operating in providing 15 0 Mb/s TV phone services and 60()Mb/s HDTV distribution services with high stability. An experimental optical Digital Crossconnect System (o ptical DCS) has also been demonstrated. Line failure restoration opera tion at 2.4 Gb/s has been successfully demonstrated. These experimenta l demonstrations prove that practical photonic switching systems are f easible with current technologies.