Channel selection and identification for coherent optical FDM systems

A novel channel selection and identification scheme for coherent optical multichannel communication systems is proposed and demonstrated. The transmitter laser diodes are frequency-modulated by sinusoidal signals with different frequencies. Channel identification is realized by means of a phase-locked loop discriminating the frequencies of the sinusoidal signals which are very weak in the intermediate frequency domain. A channel selection and identification time of less than 50 ms was achieved in a demonstration experiment with two channels.<>