An optical device transmits ECC codewords using an interleaved technique in which a single ECC codeword is transmitted over multiple optical links. In one particular implementation, the device may include an ECC circuit configured to supply ECC codewords in series, the codewords being generated by the ECC circuit based on input data and each of the codewords including error correction information and a portion of the data. The device may further include a serial-to-parallel circuit configured to receive each of the codewords in succession, and supply data units in parallel, each of the data units including information from a corresponding one of the codewords; an interleaver circuit to receive the data units in parallel and output a second data units in parallel, each of the second data units including bits from different ones of the data units; and a number of output lines, each of which supplying a corresponding one of the second data units.