Capacitors with nonlinear characteristics based on stabilized zirconia with built-in gold nanoparticles

It is shown that capacitors based on stabilized zirconia with gold nanoparticles exhibit nonlinear properties: the admittance of these capacitors depends on the amplitude of the control voltage, test-signal frequency, and temperature. The nonlinearity is due to electron capture by traps generated during nanoparticle formation. The possibility of determining the trap parameters by measuring the capacitor admittance has been established.     

Propagation of single flux quantum pulse of superconducting transmission line

Josephson tunnel junction switching by single flux quantum (SFQ) pulses generated by a two-junction interferometer and propagated on a superconducting transmission line have been investigated experimentally and by numerical simulation. High current density tunnel junctions have been used to enhance voltage SFQ pulse amplitudes and reduce junction damping parameters. The measured effective amplitudes of SFQ pulses allow an evaluation of the applicability of transmission lines to SFQ logic circuits and Josephson samplers.     

Study of the deactivation mechanisms for some constructional steels by secondary-ion mass spectrometry

Conclusions Dense corrosion layers on steels 48TS, 2Kh13, and 12Kh18N10T obtained under conditions simulating the first loop in a boron-regulated reactor are depleted in the alloying elements at the surface. Treatment with boric permanganate (pH7.4) leads to selective dissolution of the iron and partial dissolution of the iron-rich surface layer of the model oxide. Triloncitrate recipes dissolve the oxide layers efficiently when these are enriched in iron but are ineffective in dissolving chromium-bearing oxide layers.Because of these features, the performance in removing model oxide by treatment with these transformable deactivating recipes decreases in the series 48TS, 2Kh13, and 12Kh18N10T. Therefore, a basic problem in devising effective method of deactivating constructions containing low-alloy, stainless, and chromium steels is the prevision in the deactivating solution of conditions favoring relatively uniform dissolution of the oxides of iron (nickel) and the oxides of chromium. None of the recipes considered above satisfies this requirement. Further research is in hand on the possibility of realizing these conditions.Translated from Atomnaya Énergiya, Vol. 53, No. 3, pp. 171–174, September, 1982.     

A Design and New Functionality of Antiwaveguiding Vertical-Cavity Surface-Emitting Lasers for a Wavelength of 850 nm

Vertical-cavity surface-emitting lasers (VCSELs) with an aperture limited by an oxide and a resonance cavity based on GaAlAs with high Al content provide a maximum γ factor (λ/2 design) and suppression of optical power beyond the aperture. A VCSEL with two coupled cavities provides additional sharp growth of the loss of high-order lateral modes by leakage to the oxidized region and provides single-mode laser generation for an aperture diameter of up to 5 μm. Single-mode antiwaveguiding VCSELs provide ultrafast data transmission with a rate of up to 160 Gbit/s. The structure in which the active medium is placed in the lower distributed Bragg reflector and the cavity and the upper distributed Bragg reflector are dielectric, reducing the temperature shift of the radiation wavelength by a factor of 2 (to ～0.03 nm/K).     

Polarization characteristics of 850-nm vertical-cavity surface-emitting lasers with intracavity contacts and a rhomboidal oxide current aperture

The polarization characteristics of 850-nm vertical-cavity surface-emitting lasers (VCSELs) with intracavity contacts and a rhomboidal oxide current aperture are studied. It is found that radiation polarization is always directed along the minor diagonal of the rhomboidal aperture (along the [\(\overline 1 \) 10] direction) for all single-mode VCSELs. The numerical simulation of carrier transport does not reveal the significant anisotropy of carrier injection to the active region. Furthermore, an analysis of the spatial distribution of the fundamental mode for two orthogonal polarizations within an effective waveguide model shows close transverse optical-confinement factors. Optical loss anisotropy in the asymmetric microcavity and/or gain anisotropy in the strained active region are the most likely mechanisms responsible for fixing the polarization.