Uniform low-loss cyclic arrayed waveguide grating router with input splitters and output combiners

We designed and fabricated a uniform low-loss silicon-on-insulator 4 × 4 cyclic arrayed waveguide grating router (AWGR) using input splitters and output combiners at the edge channels. Our analysis revealed that the field distribution that resulted from the split/combined paths of the input/output port has better coupling efficiency with the arrayed waveguides after diffraction, thus leading to lower loss and lower non-uniformity across all input and output ports. Experimental results demonstrate a loss of non-uniformity of 0.4 dB across all 16 input-output routes, with a 3 dB improvement over the conventional design. The maximum insertion loss is reduced by 3 dB, with a minimum loss of 1.1 dB and crosstalk below -22.7 dB. The design can be extended to larger-scale AWGRs and bidirectional AWGRs for improved performance.