Experimental verification of the phase-shaped binary transmission (PSBT) effect

Using an external phase modulator, a phase signal has been superimposed to a 10-Gb/s chirp-free nonreturn-to-zero (NRZ) signal in order to extend the dispersion limit. A transmission over 146 km of standard dispersive fiber has been achieved. The phase signal shape is based on a three-bit analysis using the concepts of phase-shaped binary transmissions (PSBT). By removing or adding the phase signal, we have experimentally shown the physical concepts involved in PSBT in agreement with our simulations.