For suppressing intra-channel four wave mixing in a time division multiplexing (TDM) system, where N synchronous data streams, each having a reduced data pulse width within a bit slot timing interval, from parallel to serial form, are converted for optically bit interleaving the N synchronous data streams into the optical communication link at a nominal bit slot delay between sequential N synchronous data streams related to the bit slot timing interval to provide a serial data sequence of short optical pulses having an equal bit slot delay between sequential pulses, a sequential bit slot delay is varied between two of the short optical pulses to provide an unequal bit slot delay between sequential pulses within the serial data sequence of short optical pulses for suppression of undesired intra-channel four-wave mixing pulses among the pulses and thereby, improvement of transmission performance.