We present a closed form expression to analyse the error performance o
f a differential phase-shift keying (DPSK) digital modulation format i
n an optical soliton communication system. In the analysis we include
the effect of Gordon-Haus jitter, which is mainly due to the amplified
spontaneous emission noise of the amplifiers. Gordon-Haus jitter is f
ound to be less significant when the bit period is 15 times greater th
an the jitter variance and becomes more significant when the signal-to
-noise ratio is greater than 20 dB. Due to a good bit error rate (BER)
performance (BER approximate to 10(-20) at SNR = 21 dB), the DPSK mod
ulation format has a potential application for a high-bit-rate and low
-noise soliton communication system. (C) 1998 Elsevier Science Ltd. Al
l rights reserved.