The characteristics of novel reverse-biased waveguide phase modulators are reported. These devices, which use the translation a depletion edge, have provided highest efficiency figure merit (56 °/Vmm) ever reported for device. Furthermore, speed device is only limited by RC time constant. investigated devices were GaAs/AlGaAs ridge modulators, geometry well suited integrated optoelectronics.

A new Pb-based superconductor containing the Pb-1223 phase has been successfully synthesized by means of a high-pressure technique. Bulk superconductivity detected at temperatures below 115 K. This that superconducting homologous series, Pb-12( n -1) , exists. To date, there exist series layered cuprates for each M-(Ba, Sr)-Ca-Cu-O systems where M stands an element with atomic number between 80(Hg) and 83(Bi) except 82(Pb)–a missing link. link found.

The wavelength dependence of doped, reverse-biased channel waveguide phase modulators with very high efficiencies are reported between 1.06 μm and 1.53 μm. Figures-of-merit ranging from 61°/V mm 40°/V to 27°/V 16°/V for the TE TM modes, respectively, have been obtained. By deducting easily calculated linear electro-optic free-carrier plasma effects, data gives first real measure dispersion associated shift in absorption edge. This dispersion, which is primary contribution quadratic effect...

Silicon diffusion into GaAs from a sputtered film in closed ampoule is described. Excess arsenic pressure required the for successful diffusion. The relationship between junction depth and coefficient has been theoretically derived activation energy of Si-Si pair obtained that relation.

The characteristics of an optical waveguide phase shifter using free-carrier depletion in a reverse-biased double-heterostructure p-n junction are given for the first time. Ridge waveguides were fabricated by liquid-phase epitaxy and wet chemical etching AlGaAs/GaAs. largest phase-shifting efficiency (54°/V mm) ever reported structure was observed.

Silicon diffusion into AlxGa1−xAs (x=0–0.4) from a sputtered Si film is described. It shown that both the rate and surface concentration of decrease with increasing Al mole fraction. The behavior in discussed terms binding energy Al–As bond mixed crystal disorder.

The application of thin Si films for selective area and Zn diffusion into GaAs AlGaAs is described in detail. concentration-dependent pair coefficient the activation energy AlxGa1−xAs under As overpressure 0≤x≤0.8 are measured using both secondary ion mass spectrometry junction depth studies. Furthermore, seen to act as an ideal mask at temperatures below 750 °C. Ideal lateral profiles routinely observed these films, independent stress interface which provides new insight nature laterally...

The utilization of a telescope with large single aperture is limited by the manufacturing technique, cost, volume and weight monolithic mirror. In order to solve these problems, technology segmented synthetic was introduced. primary mirror consists several mirrors, whose misalignment errors make wavefront change drastically influence MTF optical system badly. coding (WFC) an innovative that joints design digital image processing together. By adding phase mask close pupil modulating...

Abstract Conventional methods for evaluating of fish freshness based on physiological and biochemical are often destructive, complicated, costly. This study aimed to predict the large yellow croaker which was sampled every second day in 9 consecutive days at 4°C, using computer vision technology combined with pupil color parameters different machine learning algorithms (back propagation neural network, BPNN; radial basis function network; support vector regression; random forest regression,...

Ferromagnetic-like transitions have been observed for R-Cu-O ( R= Tm and Y) samples heat-treated at 1000° C under a high pressure of 5 GPa. The transition occurs ∼30 K both Tm-Cu-O Y-Cu-O. Nearly single-phase were prepared cation ratio Tm/Cu=1.0/1.8. This phase has monoclinic I 2/ symmetry with the lattice parameters =5.660(1) Å, b =9.544(2) c =5.582(2) Å β=92.52(1)°. Compositional analyses revealed that two cations was Tm/Cu=1.00/1.87, i.e. not exactly equal to 1/2.

The (111) surfaces of Si single crystals, mechanically lapped by fine abrasives with different particle size or chemically etched, are observed from the cross-sectional direction transmission electron microscopy (TEM). On surface defect layers several µm in thickness, containing blocks, grains and cracks along nearly {100}, {110} {111} {112}, formed. as well misorientation between increases increase abrasives. etched surface, on other hand, density is so low that crystal near seems almost...

Using the Delude model. we theoretically calculate dispersion of conductivity with frequency in orthogonal direction two-dimensional black phosphorus (2D BP) <i>x</i> and <i>y</i> THz band. We find that is more sensitive to electron doping concentration. The difference between 2D BP conductivities both directions leads dielectric constant which turn can modulate light different polarization directions. polarize wave, BP-SiO<sub>2</sub> periodic sandwich...

The use of a sputtered silicon film as new type etching mask is reported for the first time. Its desirable properties arise because similar material characteristics (thermal expansion coefficient, crystal structure, smaller misfit factors) and different behavior compared to gallium arsenide. These are studied utilized in fabrication GaAs/GaAlAs double heterostructure (DH) ridge waveguide devices.

X-ray characterization of lapped surfaces Si monochromator crystals for coronary angiography was performed at 33.17 keV to find out its optimum condition obtain highest integrated intensity and a reasonable energy resolution, such as materials, diffraction indices, asymmetrical factors, states crystal surfaces. Its the full width half maximum 311 by SiC ♯1200 abrasive enhanced nine times enlarged seven large an etched one, respectively. These results meet requirements imaging in angiography....

Time-to-Digital converter (TDC) is one of the high-precision time measurement techniques. The design a TDC chip presented in this paper. This occupies cyclic tapped delay line which forms ring oscillator. Several functions are supported, include Range1, Range2, self-calibration and temperature measurement. implemented 0.18 μm 1P5M CMOS logic technology. Test results show resolution 52 ps. dynamic power current 1.5348 mA, static 116.5706 μA at 25°C 3.3 V I/O, 1.8 core voltage. can be used...

Single-mode phase modulators with high efficiency are important for coherent optical communications systems operating in the 1.0-1.6-μm wavelength range. We report on characteristics of a very efficient AlGaAs/GaAs channel waveguide modulator which uses combination reversebiased effects (including plasma effect, electrooptic and dispersion due to absorption edge shift) that both provide modulation have potential being fast, limited only by RC.1

Abstract Miniature, etching ridge InGaAsP/InP Phase Modulator with highly efficient phase shifting efficiency of 60°/V.mm and 43°/V.mm for TE TM modes, respectively, 3 dB bandwidth 650 MHz at 1.52 μm are reported. It is well suited integrated opto-electronics. Some functions depending on the devices discussed.