Investigation on the Generation of coherent optical multi-carriers using cascaded phase modulators

A simple and cost-effective technique to generate coherent optical multi-carriers by using cascaded phase modulators is proposed and investigated. A detailed theoretical analysis is presented. The phase and amplitude relation of RF signals on two concatenated phase modulators are investigated. Simulation results are in good agreement with the theoretical analysis, and the experimental performance of 22 subcarriers with amplitude difference of 5dB shows that this scheme is a promising technique for the coming Tb/s optical communication.