Asymmetrically-dilated cross-connect switches for low-crosstalk WDM optical networks

We find that the asymmetrically-dilated configuration of a 2×2 cross-connect switch is superior to the conventionally dilated configuration in terms of overall crosstalk when the levels of the bar-port crosstalk and the cross-port crosstalk of a unit switch are significantly different from each other, which is true in many types of wavelength filters for wavelength-division-multiplexing (WDM) optical-network applications. We present a recursive method to extend the principle of asymmetric dilation to larger-size cross-connect switches, and make a recommendation for a asymmetrically-dilated 4×4 cross-connect configuration