Search results for "electronics"
showing 10 items of 4340 documents
Surface plasmon polaritons in metal stripes and wires
2004
Surface plasmon polaritons (SPPs) are collective electron oscillations coupled to a light field which are propagating along the interface of a metal and a dielectric. As a surface wave, SPP modes feature properties essentially different from light-field modes in all dielectric structures. These properties could allow the realization of novel photonic devices that overcome certain limitations of conventional devices. Specifically, the realization of two-dimensional optics and light-field transport in sub-wavelength SPP waveguides seems feasible. In this review we discuss recent experimental advances regarding SPP waveguides, i.e. laterally confined metal thin films that guide SPPs. Electron-…
Propagation and scattering of light in opal heterojunctions
2006
The directionality of the polarised light transmission has been studied in heterogeneous photonic crystals based on double-film opal in comparison to homogeneous crystals on single-film opals. In spite of additional scattering at the photonic bandgap interface, ballistic propagation has been preserved. Changes of the polarisation anisotropy in hetero-opal compared to homogeneous opal have been assigned to specific mode matching conditions at the photonic bandgap interface.
<title>Structual changes of the PLZT ceramics irradiated by high-current pulsed electron beam</title>
2003
First time comprehensive study of high-current pulsed electron irradiation effects on the structural, optical and dielectric properties of relaxor (Pb(1-x)Lax)(Zr0.65Ti0.35)1-x/4O3 ceramics with x = 4 and 9.75 at.% have been provided. The electron beam had the following parameters: energy E = 250 keV, current density I = 1000 A/cm2, pulse duration τ = 300 ns, beam density - 1015 electrons/cm2 per pulse. Infrared reflectivity spectra in the region of 100 ÷ 2000 cm-1 were obtained in virgin, irradiated by 1500 pulses. The reconstruction of perovskite ABO3 structure in irradiated samples has been studied by complex use of X-ray and neutron scattering and IR spectroscopy techniques revealing th…
Integrated SINIS refrigerators for efficient cooling of cryogenic detectors
2002
In this paper we report recent results obtained with large area superconductor-insulator-normal metal-insulator-superconductor tunnel junction coolers. With the devices we have successfully demonstrated electronic cooling from 260 mK to 80 mK with a cooling power of 20 pW at 80 mK. At present, we are focusing on obtaining similar performance in cooling cryogenic detectors. Additionally, we present recent results of successful operation of a metalsemiconductor structure with a Schottky barrier acting as the tunnel barrier and the possibility to use this kind of structures for on-chip cooling.
Revisiting the electronic properties of Molecular Semiconductor – Doped Insulator (MSDI) heterojunctions through impedance and chemosensing studies
2015
Abstract The core activity of this work was to give a new interpretation of the electronic behavior of Molecular Semiconductor – Doped Insulator heterojunctions (MSDI), a new organic device combining two molecular materials with very different electronic properties. We focused on understanding the phenomenon occurring at the interface of fluorinated and non-fluorinated phthalocyanines that appears to be a determining factor for the electronic charge transport in the two-component thin film and ultimately deciding the nature of gas sensing, as illustrated with ozone and ammonia chosen as examples of accepting and donating gases. The impedance measurements showed that the Schottky contact bet…
Schottky barrier height tuning by Hybrid organic-inorganic multilayers
2014
ABSTRACTSemiconducting and insulating polymers and copolymers/Au nanograins based hybrid multilayers (HyMLs) were fabricated on p-Si single-crystal substrate by an iterative method that involves, respectively, Langmuir-Blodgett and spin-coating techniques (for the deposition of organic film) and sputtering technique (for the deposition of metal nanograins) to prepare Au/HyMLs/p-Si Schottky device. The electrical properties of the Au/HyMLs/p-Si Schottky device were investigated by current-voltage (I–V) measurements in the thickness range of 1-5 bilayers (BL).At different number of layers, current-voltage (I–V) measurements were performed. Results showed a rectifying behavior. Junction parame…
750 mW continuous-wave solid-state deep ultraviolet laser source at the 253.7 nm transition in mercury.
2007
A high-power continuous-wave coherent light source at 253.7 nm is described. It is based on a solid-state Yb:YAG disk laser with two successive frequency doubling stages and is capable of generating stable output powers of up to 750 mW. Spectroscopy of the 6 (1)S(0)-6 (3)P(1) transition of mercury has been demonstrated.
Charge Transport Properties in CZT Detectors Grown by the Vertical Bridgman Technique
2010
Great efforts are being presently devoted to the development of CdTe and CdZnTe detectors for a large variety of applications, such as medical, industrial, and space research. We present the spectroscopic properties of some CZT crystals grown by the standard vertical Bridgman method and by the boron oxide encapsulated vertical Bridgman method, which has been recently implemented at IMEM-CNR (Parma, Italy). By this technique the crystal is grown in an open quartz crucible fully encapsulated by a thin layer of liquid boron oxide. This method prevents contact between the crystal and the crucible thereby allowing larger single grains with a lower dislocation density to be obtained. Several mono…
Control of the chromatic dispersion of photonic crystal fibers for supercontinuum and photon pairs generation
2011
The interplay between chromatic dispersion and nonlinear effects is crucial for an efficient exploitation of non linear propagation in photonic crystal fibers (PCF). Once a PCF preform has been prepared, changing the parameters that control the fabrication process it is possible to adjust the dispersion properties of the fiber. In addition, it is particularly useful to develop postprocessing techniques that enable a fine adjustment of the dispersion along a section of PCF. The tapering of PCF, using a fusion and pulling technique, has been established as a rather useful technique to engineer the dispersion properties along tens of centimeters. Some of our recent experiments demonstrate that…
Single-Crystal vs Polycrystalline Gold: A Non-linear-Optics Analysis
2017
Standard gold in the field of plasmonics is obtained by evaporation or sputtering and therefore is polycrystalline. Yet, this gold presents numbers of drawbacks such as roughness, grains and ill-defined electronic band diagrams in addition to the lack of reproducibility from one instrument to another. It is, thus, beneficial to turn to a metal production that can enable well-defined and controlled gold parameters. To that end, we have explored the wet synthesis of gold nanoplates which represents a simple and robust means of obtaining single-crystal gold (Guo Z, Zhang Y, DuanMu Y, Xu L, Xie S, Gu N, Colloids Surf A 278:33–38, 2006). The synthesized nanoplates are from 50 to less than 100 nm…