Full duplex optical transceiver with remote light source for transmitter

An optical transceiver for transmitting and receiving optical signals comprises an optical signal receiver and a light modulator, the receiver and modulator being arranged such that, in use, light modulated by the modulator is received by the modulator from a source remote from the transceiver, optical signals received by the receiver are not modulated by the modulator, and light modulated by the modulator is transmitted as optical signals from the transceiver simultaneously with the reception of signals by the receiver. The light destined for the modulator may pass through the receiver first. A reflection based configuration is also disclosed.