High Baud Rate On-chip Spatial Mode Signaling Based on Tapered Asymmetric Directional Coupler

In this paper, based on integrated tapered asymmetric directional coupler, a high baud rate on-chip spatial mode signaling and manipulation is demonstrated. On chip signaling of 400Gbps (2×200Gbps) 16-ary quadrature amplitude modulation (16-QAM) and 600Gbps (6×100Gbps) quadrature phase shift keying (QPSK) signals are successfully achieved via 2×2 and 6×6 mode (de)multiplexers which supports TE 0 -TE 1 , TE 0 -TE 2 , TM 0 -TM 1 , TM 0 -TM 2 modes. The obtained bit error ratios (BERs) for the signaling of the modes are all below the soft-decision FEC (forward error correction) threshold 1.5×10 ^-2 . The results show the potential of applying the mode division multiplexing chip in the 200GbE/400GbE network.