Ultra-long Single Carrier Unrepeatered Transmission of 400 Gb/s over 542 km, 600Gb/s over 489 km, and 800 Gb/s over 437 km

We demonstrate record unrepeatered transmission of 400 Gb/s QPSK over 542.4 km, 600 Gb/s PCS-16QAM over 489.4 km, and 800 Gb/s 16-QAM over 437.7 km, with low-loss high effective-area fiber, co-directional Raman amplification and a receiver ROPA with third order pumping.