Results 1 - 10 of 22698
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[en] We have designed, fabricated and characterized integrated directional couplers capable of converting the mode of an optical dielectric waveguide into a long-range plasmon propagating along a thin metal stripe. We demonstrate that the coupling between the two types of waveguides is generally very weak unless specific conditions are met. This sensitivity could be potentially exploited in sensing applications or for developing novel active photonic components.
[en] Previous formulations of transformation optics have generally been restricted to transformations from relatively simple initial media, such as the vacuum, because of limitations due to their noncovariance. I show that a completely covariant approach enables arbitrary transformations from arbitrarily complex initial linear dielectrics.
[en] The paper gives a short introduction into some system-theoretic aspects and features of dielectric measurements by periodic wideband signals. Based on these considerations, a related measurement concept will be presented which is well suited for both compact device implementation and monolithic integration. Some implementation examples are shown and first measurement results are presented.
[en] The theory of spontaneous emission in dielectric media is extended to take proper account of dispersion and local field corrections. For the case of spontaneous emission in a plasma or radiative electron-hole recombination in a semiconductor, there are effectively no local field corrections. A shift of emission lines due to a dispersive host medium is predicted and interpreted. The corrections to spontaneous and stimulated emission due to dielectric interfaces in microcavity lasers are discussed
[en] Highlights: • Nano-Fe3O4/PANI composites have negative permittivity which is significantly affected with the nano-Fe3O4 content. • Improved structure model of “crystal-nano wire” is used to explain the generation mechanism of negative permittivity. • Negative dielectric phenomenon of nano-Fe3O4/PANI composites is explained from the point of structure.
[en] The resistive switching phenomenon has attracted much attention recently for memory applications. It describes the reversible change in the resistance of a dielectric between two non-volatile states by the application of electrical pulses. Typical resistive switching memories are two-terminal devices formed by an oxide layer placed between two metal electrodes. Here, we report on the fabrication and operation of a three-terminal resistive switching memory that works as a reconfigurable logic component and offers an increased logic density on chip. The three-terminal memory device we present is transparent and could be further incorporated in transparent computing electronic technologies
[en] The wet etching properties of a HfSiON high-k dielectric in HF-based solutions are investigated. HF-based solutions are the most promising wet chemistries for the removal of HfSiON, and etch selectivity of HF-based solutions can be improved by the addition of an acid and/or an alcohol to the HF solution. Due to densification during annealing, the etch rate of HfSiON annealed at 900 0C for 30 s is significantly reduced compared with as-deposited HfSiON in HF-based solutions. After the HfSiON film has been completely removed by HF-based solutions, it is not possible to etch the interfacial layer and the etched surface does not have a hydrophobic nature, since N diffuses to the interface layer or Si substrate formation of Si-N bonds that dissolves very slowly in HF-based solutions. Existing Si-N bonds at the interface between the new high-k dielectric deposit and the Si substrate may degrade the carrier mobility due to Coulomb scattering. In addition, we show that N2 plasma treatment before wet etching is not very effective in increasing the wet etch rate for a thin HfSiON film in our case. (semiconductor technology)
[en] Highlights: • Characterization of a polymer network with spiroacetal moieties and riboflavin. • The thermal stability of the new compounds is close to that of the starting copolymer. • The dynamic of the system can be detected by fluorescence spectroscopy. • Significant disturbance into the system can be evaluated by circular dicroism. • The dielectric spectroscopy confirms the polymer network formation.