High-Capacity Multi-Stage Operation of Polarization-Diversity Silicon Photonics 8 × 8 Optical Switch

For practical and wide use of optical switches, cascadability and high throughput are of great significance. We demonstrate up to 8-stage cascaded operation of a polarization-independent silicon photonics 8 × 8 optical switch where 11-channel 32/44-Gbaud DP-16QAM signals are loaded up on all the paths in a cyclic way. The results verify that the 8 × 8 switch is capable of offering a throughput of 48.2 Tb/s with a wall-plug energy efficiency of 0.37 pJ/bit. Using an additional optical module with the characteristics equivalent to the 8 × 8 switch, 9-stage cascaded operation is also emulated. The successful performance observed in these experiments promises the realization of optical switch fabrics with higher port counts by arranging the 8 × 8 switches in a multi-folded Clos network.