With the arrival of wavelength division multiplexed (WDM) systems carrying large numbers of wavelength channels, it appears that new cross-connect architectures that allow large numbers of wavelength channels to cross-connect at the wavelength granularity level are required. We propose a number of such architectures. The different architectures are compared in terms of complexity, cost, loss, crosstalk and filter narrowing. An analysis of the various nonblocking properties of such cross-connects is also described.
Gordon Wilfong, Benny Mikkelsen, Chris Doerr, and Martin Zirngibl, "WDM Cross-Connect Architectures with Reduced Complexity," J. Lightwave Technol. 17, 1732- (1999)