Method and apparatus for data recovery in optical transmission systems include parallel detection subcircuits for determining output values of sequentially provided optical data bits such that sequentially provided optical data bits are alternately processed by respective ones of the parallel detection subcircuits. For example, in one embodiment of the present invention, clock values to be used for timing provided to the first parallel detection subcircuit are 180° out of phase with clock values provided to the second parallel detection subcircuit, such that the first parallel detection subcircuit and the second parallel detection subcircuit alternately process input optical data bits according to odd valued clock signals and even valued clock signals. Furthermore, the outputs of the parallel detection subcircuits are connected crosswise to provide control signals for their parallel counterparts. In principle, various decisions are made using decision circuits and desired output values are selected based on the previously decided bits.