N-degree ROADM architecture comparison: Broadcast-and-select versus route-and-select in 120 Gb/s DP-QPSK transmission systems

ROADM systems utilizing 4- and 9-degree broadcast-and-select or route-and-select architectures are studied experimentally with 120 Gb/s DP-QPSK transmission. Effects arising from passband narrowing and crosstalk accumulation due to non-ideal WSS filtering are considered concurrently.