We show that electroabsorption modulators (EAMs) can be used as the basis of serial-to-parallel and parallel-to-serial convertors, the latter by demonstrating the use of an EAM to extract a 10 Gbit/s channel from a 100 Gbit/s serial bit-stream. We envisage that a further stage of serialisation or parallelisation would be carried out in the electrical domain at the transmitter and receiver respectively to fit in with the requirements of the backplane.