Patent ID: 7933519

Claim:
An optical cross-connect switching optical signals of N routes (N=1, 2, . . . ), the optical cross-connect comprising: 2-input N-output (2×N) wavelength selective switches coupled respectively to N input routes; and N-input 2-output (N×2) wavelength selective switches coupled respectively to N output routes; wherein: one input port of the nth 2×N wavelength selective switch (n=1, 2, . . . N) coupled to the nth input route receives an optical signal from the nth input route while the other input port thereof receives an optical add signal from the nth add route; and one output port of the nth N×2 wavelength selective switch outputs an optical signal to the nth output route while the other output port thereof outputs an optical drop signal to the nth drop route; and wherein: (N−1) out of N output ports of the nth 2×N wavelength selective switch are connected respectively to (N−1) input ports of (N−1) N×2 wavelength selective switches other than the nth N×2 wavelength selective switch coupled to the nth output route; the remaining output port of the nth 2×N wavelength selective switch outputs an optical drop signal to the nth drop route; and the remaining input port of the nth N×2 wavelength selective switch receives the optical add signal from the nth add route.