Soliton interaction penalty reduction by receiver filtering

We present the first detailed numerical study of the impact of receiver low-pass filtering in soliton interaction-limited communication systems. We propagate 40-Gb/s pseudorandom bit sequences (PRBS's) of 2/sup 8/-1 solitons up to one soliton collision distance (z/sub c/) and optimize the filter bandwidth to minimize the interaction induced eye opening penalty. The distance at 0.5-dB penalty is increased over 40% through filtering. The penalty is essentially pulsewidth independent when considering distances normalized by z/sub c/. We also show that PRBS's of at least 2/sup 8/-1 solitons are required to accurately simulate random data.