Transmission and optical label swapping for 4/spl times/40 gb/s WDM signals deploying orthogonal ASK/DPSK labeling

In this letter, we report a novel amplitude shift keying/differential phase-shift keying (ASK/DPSK) optical packet encoding method that can significantly reduce the crosstalk between the ASK payload and the DPSK label through spectrum shaping. We demonstrate wavelength-division-multiplexing (WDM) transmission for 4/spl times/40 Gb/s labeled return-to-zero signals, including label swapping by Kerr switching of one of the channels, with an overall penalty of 3.3 dB for the payload and 0.3 dB for the label, clearly validating this orthogonal modulation scheme as a potential solution for future ultrahigh-speed Internet protocol-over-WDM networks.