An optical transmitter, comprising: a master laser device for generating a master signal; a plurality of slave laser devices, injected with the master signal such that signals generated by the slave laser devices are phase-locked with the master signal; an input for receiving one or more data streams to be transmitted, the one or more data streams being used to amplitude-modulate respectively the slave laser devices, such that each signal generated by the slave laser devices respectively comprises a modulated part and a carrier part; and an interfering arrangement, for destructively interfering the signals generated by the slave laser devices with a signal derived from the master signal, so as to generate an output signal in which the carrier part is at least partially cancelled; wherein: signals generated by at least one of the plurality of slave laser devices are shifted in phase with respect to signals generated by at least another one of the plurality of slave laser devices; signals generated by at least a first slave laser device of the plurality of slave laser devices have a different amplitude to signals generated by at least a second slave laser device of the plurality of slave laser devices; the output signal corresponds to a combination of the signals generated by each of the plurality of slave laser devices; and the interfering arrangement is further for combining signals generated by each of the slave laser devices. a master laser device for generating a master signal; a plurality of slave laser devices, injected with the master signal such that signals generated by the slave laser devices are phase-locked with the master signal; an input for receiving one or more data streams to be transmitted, the one or more data streams being used to amplitude-modulate respectively the slave laser devices, such that each signal generated by the slave laser devices respectively comprises a modulated part and a carrier part; and an interfering arrangement, for destructively interfering the signals generated by the slave laser devices with a signal derived from the master signal, so as to generate an output signal in which the carrier part is at least partially cancelled; wherein: signals generated by at least one of the plurality of slave laser devices are shifted in phase with respect to signals generated by at least another one of the plurality of slave laser devices; signals generated by at least a first slave laser device of the plurality of slave laser devices have a different amplitude to signals generated by at least a second slave laser device of the plurality of slave laser devices; the output signal corresponds to a combination of the signals generated by each of the plurality of slave laser devices; and the interfering arrangement is further for combining signals generated by each of the slave laser devices. signals generated by at least one of the plurality of slave laser devices are shifted in phase with respect to signals generated by at least another one of the plurality of slave laser devices; signals generated by at least a first slave laser device of the plurality of slave laser devices have a different amplitude to signals generated by at least a second slave laser device of the plurality of slave laser devices; the output signal corresponds to a combination of the signals generated by each of the plurality of slave laser devices; and the interfering arrangement is further for combining signals generated by each of the slave laser devices.