An optical communication system comprising: a plurality of optical remodulators each for receiving an input from a respective one of a plurality of optical transmitters (22, 24, 25); an optical combiner for combining the outputs provided by each of the optical remodulators, the optical combiner for optically communication with an optical waveguide, and the optical combiner for combining plural optical wavelengths to form a multiplexed optical signal output; each optical remodulator configured to receive, from a respective one of the optical transmitters (22, 24, 25), an information-bearing optical signal at a transmission wavelength λ Ti, where i is an integer, and output an information-bearing optical signal at a different reception wavelength λ j, where j is an integer, each remodulator comprising: an electro-optical converter and an amplifier, the electro-optical converter for receiving the respective information-bearing optical signal at the transmission wavelength λ Ti and outputting a corresponding electrical signal which includes the information from the optical signal at the transmission wavelength λ Ti, the amplifier being arranged to amplify the received electrical signal; a filter arranged to waveshape the amplified electrical signal and a limiting amplifier arranged to further amplify the waveshaped electrical signal; a laser control and a laser for emitting a non-information-bearing optical signal at the respective reception wavelength λ j; an external modulator and a modulator drive for driving the external modulator, the external modulator arranged to optically communicate with an output waveguide of the laser for imparting information from an electrical signal input to the external modulator onto the non-information-bearing optical signal; and characterised by comprising: a forward error correction encoder configured to encode the further amplified electrical signal in accordance with a forward error correction coding algorithm and output an FEC encoded signal to the modulator drive. a plurality of optical remodulators each for receiving an input from a respective one of a plurality of optical transmitters (22, 24, 25); an optical combiner for combining the outputs provided by each of the optical remodulators, the optical combiner for optically communication with an optical waveguide, and the optical combiner for combining plural optical wavelengths to form a multiplexed optical signal output; each optical remodulator configured to receive, from a respective one of the optical transmitters (22, 24, 25), an information-bearing optical signal at a transmission wavelength λ Ti, where i is an integer, and output an information-bearing optical signal at a different reception wavelength λ j, where j is an integer, each remodulator comprising: an electro-optical converter and an amplifier, the electro-optical converter for receiving the respective information-bearing optical signal at the transmission wavelength λ Ti and outputting a corresponding electrical signal which includes the information from the optical signal at the transmission wavelength λ Ti, the amplifier being arranged to amplify the received electrical signal; a filter arranged to waveshape the amplified electrical signal and a limiting amplifier arranged to further amplify the waveshaped electrical signal; a laser control and a laser for emitting a non-information-bearing optical signal at the respective reception wavelength λ j; an external modulator and a modulator drive for driving the external modulator, the external modulator arranged to optically communicate with an output waveguide of the laser for imparting information from an electrical signal input to the external modulator onto the non-information-bearing optical signal; and characterised by comprising: a forward error correction encoder configured to encode the further amplified electrical signal in accordance with a forward error correction coding algorithm and output an FEC encoded signal to the modulator drive. an electro-optical converter and an amplifier, the electro-optical converter for receiving the respective information-bearing optical signal at the transmission wavelength λ Ti and outputting a corresponding electrical signal which includes the information from the optical signal at the transmission wavelength λ Ti, the amplifier being arranged to amplify the received electrical signal; a filter arranged to waveshape the amplified electrical signal and a limiting amplifier arranged to further amplify the waveshaped electrical signal; a laser control and a laser for emitting a non-information-bearing optical signal at the respective reception wavelength λ j; an external modulator and a modulator drive for driving the external modulator, the external modulator arranged to optically communicate with an output waveguide of the laser for imparting information from an electrical signal input to the external modulator onto the non-information-bearing optical signal; and a forward error correction encoder configured to encode the further amplified electrical signal in accordance with a forward error correction coding algorithm and output an FEC encoded signal to the modulator drive.