Performance of coherent optical phase diversity systems affected by chromatic dispersion induced PM-AM conversion noise

The performance of phase diversity ASK systems affected by the laser phase noise conversion to intensity noise, due to fibre chromatic dispersion, is analysed and the power penalty incurred due to this noise is evaluated as a function of transmitter source linewidth and fibre chromatic dispersion. As an example, considering signal transmission at 10 Gbit/s-1 through conventional single-mode fibres operating in the low-loss optical region, the power penalty at a bit error rate of 10-11 is shown to be below 0.5 dB when the source linewidth to bit-rate ratio is less than 19% by using two-branch phase diversity ASK receivers. The above effect is seen to be less severe for the three-branch phase diversity ASK schemes and most severe in intensity modulation and direct detection systems. © 1995 Taylor & Francis Ltd.