Multi-dimensional formats for flexible optical networks with cascaded optical add/drop nodes

We propose 8-dimensional 8192QAM to balance the nonlinear transmission performance and add/drop induced optical filtering. Simulations show that this format outperforms conventional PDM-16QAM, PDM-8QAM, and 4-dimensional 128QAM for 200-Gbit/s/channel optical networks with cascaded add/drop nodes.