Patent ID: 7430346

Claim:
An optical switching apparatus, comprising: a first stage, for selectively adapting component channel wavelengths of N received wavelength division multiplexed (WDM) optical signals to provide thereby 2N first processed WDM optical signals, where N is an integer; a first pair of N×N cyclic arrayed waveguide gratings (AWG), for cyclically routing component channel wavelengths of the 2N first processed WDM optical signals to provide thereby 2N first routed WDM optical signals; a second stage, for selectively adapting component channel wavelengths of the 2N first routed WDM optical signals to provide thereby 2N second processed WDM optical signals; 2N WDM combiners, each for combining two second processed WDM optical signals that include one from each of the first pair of N×N cyclic AWGs to provide thereby a combined WDM optical signal; a second pair of N×N cyclic AWGs, each for cyclically routing component channel wavelengths of at least a respective combined WDM optical signal to provide thereby N second routed WDM optical signals; a third stage, for selectively adapting component channel wavelengths of the 2N second routed WDM optical signals to provide thereby 2N third processed WDM optical signals; and N combiners, for combining corresponding component wavelengths for each one of N WDM optical signals provided by said second pair of N×N cyclic AWGs.