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P. Bayvel

Publications and source records attributed to P. Bayvel.

6 recordsLinked to original sources

A Closed-form Expression for the Gaussian Noise Model in the Presence of Raman Amplification

A closed-form model for the nonlinear interference (NLI) in Raman amplified links is presented, the formula accounts for both forward (FW) and backward (BW) pumping schemes and inter-channel stimulated Raman scattering (ISRS) effect. The formula also accounts for an arbitrary number of pumps, wavelength-dependent fibre parameters, launch-power profiles, and is tested over a distributed Raman-amplified system setup. The formula is suitable for ultra-wideband (UWB) optical transmission systems and is applied in a signal with 13~THz optical bandwidth corresponding to transmission over the S-, C-, and L- band. The accuracy of the closed-form formula is validated through comparison with numerical integration of the Gaussian noise (GN) model and split-step Fourier method (SSFM) simulations in a point-to-point transmission link.

eess.SP

Design and optimisation of quantum logic circuits for a three-qubit Deutsch-Jozsa algorithm implemented with optically-controlled, solid-state quantum logic gates

We analyse the design and optimisation of quantum logic circuits suitable for the experimental demonstration of a three-qubit quantum computation prototype based on optically-controlled, solid-state quantum logic gates. In these gates, the interaction between two qubits carried by the electron-spin of donors is mediated by the optical excitation of a control particle placed in their proximity. First, we use a geometrical approach for analysing the entangling characteristics of these quantum gates. Then, using a genetic programming algorithm, we develop circuits for the refined Deutsch-Jozsa algorithm investigating different strategies for obtaining short total computational times. We test two separate approaches based on using different sets of entangling gates with the shortest possible gate computation time which, however, does not introduce leakage of quantum information to the control particles. The first set exploits fast approximations of controlled-phase gates as entangling gates, while the other one arbitrary entangling gates with a shorter gate computation time compared to the first set. We have identified circuits with consistently shorter total computation times when using controlled-phase gates.

quant-ph

Diffraction grating revisited: a high-resolution plasmonic dispersive element

The spectral dispersion of light is critical in applications ranging from spectroscopy to sensing and optical communication technologies. We demonstrate that ultra-high spectral dispersion can be achieved with a finite-size surface plasmon polaritonic (SPP) crystal. The 3D to 2D reduction in light diffraction dimensions due to interaction of light with collective electron modes in a metal is shown to increase the dispersion by some two orders of magnitude, due to a two-stage process: (i) conversion of the incident light to SPP Bloch waves on a nanostructured surface and (ii) Bloch waves traversing the SPP crystal boundary. This has potential for high-resolution spectrograph applications in photonics, optical communications and lab-on-a-chip, all within a planar device which is compact and easy to fabricate.

cond-mat.str-el