Low-loss and large-scale optical switch utilizing asymmetric-port-count cyclic AWGs

We propose a novel optical switch configuration that utilizes erbium-doped fiber amplifiers (EDFAs) and asymmetric-port-count cyclic arrayed-waveguide gratings (AWGs). By optimizing the number of utilized input ports of the cyclic AWGs, our proposed scheme can reduce total switch loss and hence relax requirements for EDFAs in terms of gain and maximum output power. To verify effectiveness of the proposed scheme, we fabricate a 90×90 cyclic AWG using planar-lightwave-circuit technology and construct part of a 720×720 optical switch. Good transmission characteristics are confirmed via bit-error-ratio measurements.