Kerr nonlinearity imposes a limit on the achievable transmission performance and capacity of optical fibre communication links. We show that the nonlinear distortions of a pair of phase-conjugated twin waves are essentially anticorrelated, so cancellation of signal-to-signal nonlinear interactions can be achieved by coherently superimposing the twin waves at the end of the transmission line. We...

Optical nonlinearities are known to coherently couple amplitude and phase of light, which can result in the formation periodic waveforms. Such waveforms referred as optical frequency combs. Here we show that Bloch gain---a nonclassical phenomenon was first predicted 1930s---can play an essential role comb formation. We develop a self-consistent theoretical model considers all aspects dynamics: ...

Entanglement [1, 2] is one of the most intriguing feature of quantum mechanics, having myriads of potential applications in quantum information and communication [3]. So far, preparation and manipulation of entanglement has been successfully demonstrated in microscopic systems, such as atoms , photons, ions [4–6] etc. However, the validity of entanglement in the macroscopic realm is still a deb...

This paper numerically investigated the evolution of the degree of polarization of individual channels and their Stokes parameters in a wavelength division multiplexed (WDM) system in which Kerr nonlinearity and chromatic dispersion are taken into account but in which polarization mode dispersion as well as polarization-dependent loss and gain are neglected. We compared the results to a mean fi...

In this paper, with the weak cross-Kerr nonlinearity, we first present a special experimental scheme called controlled-path gate with which the realization of all possible bipartite positive-operator-value measurements of two-photon polarization states may be nearly deterministic. Following the same technique, the realization of quantum control gates, including the controlled-NOT gate, Fredkin ...

Bistable responses of Fabry–Pérot cavities and all-optical arrays, in the presence of weak diffraction and strong diffusion, are studied both analytically and numerically. The model is a pair of nonlinear Schrödinger equations coupled through a diffusion equation. The numerical computations are based on a split-step method with three distinct characteristics. This bistable nonlinear system, wit...