LAUSR

Abstract This paper investigates a novel demultiplexing scheme for Nyquist optical time-division multiplexed (N-OTDM) signal using a single commercially-available IQ modulator. With only a free-run LO cascaded with a RF-driven IQ modulator at the receiver side, the proposed scheme enables N-OTDM signal demultiplexing with extremely simple structure. The feasibility and detailed influence mechanism on demultiplexing performance are firstly investigated through numerical simulation, which indicates that the insufficient suppressed high-order sideband of the generated comb from the IQ modulator is the main limiting factor that degrades the demultiplexing performance. In addition, this scheme is also experimentally demonstrated in a 160 GBaud to 40 GBaud N-OTDM demultiplexing experiment. Experimental results show that about 6.8 dB required-OSNR improvement (@BER=1E-4) is observed compared with Gaussian sampling with the same pulse-width.