Nonlinear-optical frequency-doubling meta-reflector: pulsed regime

The properties of backward-wave second harmonic meta-reflector operating in pulse regime are investigated. We show that ratio of the income pulse length to the thickness of the metaslab determines its important operational properties which are in contrast with those manifested at common second harmonic generation settings.Comment: 6 pages, 3 figure

Second harmonic generation and pulse shaping in positively and negatively spatially dispersive nanowaveguides: comparative analysis

Comparative analysis of second harmonic generation in ordinary and backward-wave settings is presented. Extraordinary properties of frequency doubling nonlinear optical reflectivity and pulse shaping through phase matching of ordinary and backward electromagnetic waves in the nanowaveguides with mixed negative/positive spatial dispersion is demonstrated with numerical simulations.Comment: 10 pages, 5 figure

Perturbation of spectra and spectral subspaces

We consider the problem of variation of spectral subspaces for linear self-adjoint operators under off-diagonal perturbations. We prove a number of new optimal results on the shift of the spectrum and obtain (sharp) estimates on the norm of the difference of two spectral projections

Critical behavior of the Random-Field Ising model at and beyond the Upper Critical Dimension

The disorder-driven phase transition of the RFIM is observed using exact ground-state computer simulations for hyper cubic lattices in d=5,6,7 dimensions. Finite-size scaling analyses are used to calculate the critical point and the critical exponents of the specific heat, magnetization, susceptibility and of the correlation length. For dimensions d=6,7 which are larger or equal to the assumed upper critical dimension, d_u=6, mean-field behaviour is found, i.e. alpha=0, beta=1/2, gamma=1, nu=1/2. For the analysis of the numerical data, it appears to be necessary to include recently proposed corrections to scaling at and beyond the upper critical dimension.Comment: 8 pages and 13 figures; A consise summary of this work can be found in the papercore database at http://www.papercore.org/Ahrens201

Simulation study of gust alleviation in a tilt rotor aircraft, volume 1

The response to vertical turbulence in cruise of the HTR XV-15 design is studied using simulation techniques. This design is a modified version of the XV-15 with a hingeless fiberglass soft-in-plane rotor system. The parameters of a gust alleviation system are determined and the performance of the system is evaluated over a range of cruise velocities and altitudes

Generalized synchronization: a modified system approach

The universal mechanism resulting in the generalized synchronization regime arising in the chaotic oscillators with the dissipative coupling has been described. The reasons of the generalized synchronization occurrence may be clarified by means of a modified system approach. The main results are illustrated by unidirectionally coupled Rossler systems, Rossler and Lorenz systems and logistic maps.Comment: 4 pages, 2 figure