Impact of crosstalk in an arrayed-waveguide router on an optical add-drop multiplexer

The impact of crosstalk in an arrayed-waveguide (AWG) router on the perform ance of an N-channel optical add-drop multiplexer (OADM) with m add/drop ch annels and n-pass channels is theoretically investigated. A single arrayed- waveguide router is simultaneously used for multiplexing and demultiplexing . This results in crosstalk not only from the incoming channels, but from t he outgoing channels as well. We show that the performance of the OADM degr ades as either N or m are increased, suggesting that the number of channels in a network based on OADM's is limited by crosstalk in the AWG router. Wh en an optical filter is added at the output of the OADM the digital signal- to-noise ratio Q is independent of N and rn, and within a few tenths of a d ecibel of the perfect filtering case.