Nonlinear inverse synthesis and eigenvalue division multiplexing in optical fiber channels.

We scrutinize the concept of integrable nonlinear communication channels, resurrecting and extending the idea of eigenvalue communications in a novel context of nonsoliton coherent optical communications. Using the integrable nonlinear Schrödinger equation as a channel model, we introduce a new approach-the nonlinear inverse synthesis method-for digital signal processing based on encoding the information directly onto the nonlinear signal spectrum. The latter evolves trivially and linearly along the transmission line, thus, providing an effective eigenvalue division multiplexing with no nonlinear channel cross talk.

Power pre-emphasis for suppression of FWM in coherent optical OFDM transmission.

Four-wave-mixing (FWM) due to the fiber nonlinearity is a major limiting factor in coherent optical OFDM transmission. We propose to apply power pre-emphasis, i.e.

Random walks and random numbers from supercontinuum generation.

We report a numerical study showing how the random intensity and phase fluctuations across the bandwidth of a broadband optical super-continuum can be interpreted in terms of the random processes of random walks and Lévy flights. We also describe how the intensity fluctuations can be applied to physical random number generation. We conclude that the optical supercontinuum provides a highly versatile means of studying and generating a wide class of random processes at optical wavelengths.

Time domain all-optical signal processing at a RZ optical receiver.

We propose a new all-optical signal processing technique to enhance the performance of a return-to-zero optical receiver, which is based on nonlinear temporal pulse broadening and flattening in a normal dispersion fiber and subsequent slicing of the pulse temporal waveform. The potential of the method is demonstrated by application to timing jitter- and noise-limited transmission at 40Gbit/s.