We theoretically analyze a new class of aperiodic phase mismatch. The phase-matching function that is chosen depends on the calculated second-harmonic amplitude generated in the device during the propagation of the fundamental beam at given input intensity and wavelength. We show that, in such a configuration, the fields evolve toward the eigenmodes of a x (2) two-wave mixing process. Hence a c...

We predict the existence of coupled plasmon-phonon excitations in graphene by using the self-consistent linear response formalism. The unique electron-phonon interaction in graphene leads to unconventional mixing of plasmon and optical phonon polarizations. We find that longitudinal plasmons couple exclusively to transverse optical phonons, whereas graphene’s transverse plasmons couple only to ...

Polar optical phonons at GaAs|Al (x) Ga (1−x) As interfaces: influence of the concentration of Al Abstract We study long-wavelength polar optical modes at semiconductor interfaces of GaAs|Al (x) Ga (1−x) As and take into account influence of the Al concentration. We have considered two cases in which the interface is kept at unfixed and fixed electrostatic potential. The spectrum of excitation ...

We have performed a statistical analysis of a sample of 1100 extra-galactic rotation measures (RMs) obtained from the literature. Using a subsample of approximately 800 reliable RMs we compute a rotation measure sky and determine reliable large scale features for the line of sight Galactic magnetic field. We find that the influence of the Milky Way can be seen up to roughly 30◦ on either side o...

MkIIGB divertor tiles exposed in JET for the 1998–2001 and 1999–2001 campaigns have been used to assess the amount of beryllium and carbon deposited at the inner divertor wall. Total amount of Be at the inner divertor tiles was determined and integrated toroidally. Results were compared with data obtained with optical spectroscopy and good agreement was obtained. The amount of deposited C was c...

due to the effect of aerosols present in the atmosphere on the satellite images, the study of the effect of local aerosols distribution on the satellite images is important. on the other hand, the study shows that the effect of aerosols on the greenhouse gases and consequently on climate is also undeniable and as a result, this puts more emphasize on the necessity of this study. lack of informa...

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A fiber optic channel is modeled in a variety of ways; from the simple additive white complex Gaussian noise model, to models that incorporate memory in the channel. Because of Kerr nonlinearity, a simple model is not a good approximation to an optical fiber. Hence we study a fiber optic channel with finite memory and provide an achievable bound on channel capacity that improves upon a previous...

S. Saberi-Pouya, 2 T. Vazifehshenas, ∗ T. Salavati-fard, M. Farmanbar, and F. M. Peeters Department of Physics, Shahid Beheshti University, G. C., Evin, Tehran 1983969411, Iran Department of Physics, University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerpen, Belgium Department of Physics and Astronomy, University of Delaware, Newark, DE 19716, USA Faculty of Science and Technology and MESA...

Silicon thin layers are deposited on glass substrates with the thickness of 103 nm, 147 nm and 197 nm. The layers are produced with electron gun evaporation method under ultra-high vacuum condition. The optical Reectance and the Transmittance of produced layers were measured by using spectrophotometer. The optical functions such as, real and imaginary part of refractive index, real and imaginar...