Pilot tones in networks with nonlinear elements

Transmission of pilot tones for supervision and management of all-optical networks deploying nonlinear elements, like interferometric wavelength converters, is experimentally investigated. Experiments show that the pilot tone is affected due to the converters nonlinear transfer function. A novel scheme to block and reinsert pilot tones using an all-active interferometric Mach-Zehnder wavelength converter is demonstrated experimentally in a 10-Gb/s all-optical wavelength conversion experiment, where 30-dB suppression of a /spl sim/100-kHz pilot tone is obtained.