All-optical demultiplexing of Nyquist OTDM signal using a biorthogonal Nyquist gate

We present an all-optical method for demultiplexing Nyquist optical time division multiplexed (OTDM) signals using a biorthogonal Nyquist gate, which is a Nyquist gate of reduced pulse width. The biorthogonality between the Nyquist symbol and Nyquist gate creates an intersymbol interference (ISI) free spectral region in the mixed product that theoretically allows for complete elimination of ISI in the demultiplexer. Furthermore, this format transparent all-optical method produces a Nyquist signal on the output suitable for further optical processing and multiplexing. We analyze the performance of this approach through simulation in the presence of nonidealities of imperfect pulse shape, timing jitter, and dispersion. Finally, we experimentally demonstrate the performance of this approach operating on an 80-GBd Nyquist OTDM signal. (C) 2017 Optical Society of America under the terms of the OSA Open Access Publishing Agreement