Impact of 1/f-type FM noise on coherent optical communications

When a semiconductor laser operates in a high power state, the l/f-type FM noise is a dominant cause of spectral broadening. The degradation of the bit error rate performance of the heterodyne DPSK optical communication system due to such 1/f noise is calculated. The result shows that the 1/f noise is much less harmful than the white noise originated from spontaneous emission events.