抄録
An optical switch is one of the key elements in advanced high-speed and large-capacity WDM optical transport networks, in particular, to implement protection and restoration functionality in photonic layers. Optical switch architecture technology for protection and restoration is reviewed, focusing coexistence with the installed SONET/SDH system over WDM and in-service scalability from 1:1 to optical rings/meshes as well as low insertion loss and switching speed.