All-optical subcarrier labeling based on the carrier suppression of the payload

We report on a new approach to all-optical subcarrier labeling based on sideband generation through carrier-suppression of the payload. The experimental transmission over 50-km standard fiber of a 10-Gb/s payload data multiplexed with a synchronized 1.25-Gb/s subcarrier label is carried out with less than 1-dB receiver power penalty, clearly demonstrating the feasibility of this sideband optical labeling scheme. The requirements to the modulation index and dc bias along with the limitation of the input extinction ratio are discussed.