50 Gbps data transmission through amorphous silicon interlayer grating couplers with metal mirrors

The fabrication of highly efficient interlayer grating couplers for multilayered a-Si:H waveguides by introducing two metal mirrors to reflect back the diffracted light was demonstrated. The coupling efficiency from one layer to the next was 83% (loss of 0.8 dB). The 50 Gbps signals were successfully transmitted from one layer to the next without any eye degradation.