An apparatus and method are provided for bit synchronization in an optical time division multiplexed communication system. The apparatus is couplable to an optical gate, such as an optical demultiplexer. The apparatus includes a programmable optical delay line couplable to an input clock; an optical synchronizer coupled to the programmable optical delay line and couplable to the optical gate; and a processor coupled to the programmable optical delay line and to the optical synchronizer. The processor includes program instructions to track bit synchronization between a clock pulse and a selected data bit during a communication session; and when a bit tracking range is approaching a predetermined limit, the processor has further instructions to interrupt the communication session, return the bit tracking range to a zero offset and correspondingly adjust a programmable delay, and resume the communication session.