Coherent optical multicarrier systems

Optical coherent multicarrier systems with highly selective tunable optical heterodyne receivers can be used for transmission and switching of broadband signals. Some technical solutions for coherent bidirectional subscriber lines, a ten-channel distribution system, and a switching setup with computer-controlled receiver tuning are presented. The laboratory experiments, including carrier-frequency stabilization, multiplexing, and demultiplexing, as well as the fiber components used, are described. The influence of fiber nonlinearities on multicarrier transmission is considered.