Linearised electro-optical modulation under concurrent transmissions separated by a wide frequency span

Analog Radio-over-Fiber (a-RoF) has been the subject of increased interest in relation to next-generation optical networks due to its spectral efficiency and lower deployment cost. Nonetheless, some complexity arises from electro-optical conversion of the information signal due to the non-linear characteristic of the modulator's transfer function which causes inter-channel interference and poses a severe limitation to achievable error-free transmission. Furthermore, Harmonics Distortion (HD) resulting from employment of a high modulation depth may restrict the availability of clear frequencies for transmission of concurrent data. In this work, second and third order distortions have been optically compensated by a feed forward technique when one of two concurrent data transmission carriers occupies the same band as the other's second harmonic. Distortions reduction in both channels simultaneously results in up to 9 dB EVM improvement, which can extend the error-free range of a-RoF transmission up to 45 km.