Low crosstalk devices for wavelength-routed networks

Over the last year, homodyne beat noise and bandwidth narrowing due to filter concatenation have been identified as major problems for large wavelength-routed networks. These problems will become more acute and will interact at the design stage, as wavelength channel spacings are decreased and as the channel bit rate is increased, leading to the requirement for devices with high fractional bandwidth per channel and with very low (<-50 dB) crosstalk. We explore the fundamental limits to crosstalk in optical routing components, and propose new design concepts for wavelength demultiplexers/multiplexers and space switches that have the potential to meet these strict performance requirements