Numerical Study of Cascadability Performance of Continuous Spectrum Wavelength Blocker/Selective Switch at 10/40/160 Gb/s

Wavelength selective switches (WSS) and wavelength blockers (WB) are crucial elements in reconfigurable optical add-drop multiplexers and cross-connect nodes. For the "continuous spectrum" WB/WSS (CS-WB/WSS), the overall filtering passband of the WSS device can be adjusted in a quasi-continuous way by grouping two or more adjacent pixels offering enhanced switching flexibility at arbitrary channel spacing or multiline rates. However, loss and group delay ripples appear at each slot boundary causing degradations to the transmitted signal. In this paper, a system perspective analytical model has been developed. Through this model and detailed simulation studies, the relative impact of each imperfection on the overall cascadability performance of the WB/WSS is investigated. Different switching scenarios at various line rates (10, 40, and 160 Gb/s) have been considered and the corresponding specifications for the WSS device have been identified