Description of the Mueller Matrix for Multiple Scatteringat 90°

Mueller matrix elements are presented represen ting scatter to 90° from an incident polarized laser beam. The cases considered include five particle sizes (such as l.24 μm, 0.494 μm, 0.36 μm, 0.123 μm, and 0.065 μm), two concentr ations (such as 0.002 5% and 0.005% by volume), and three detector depths (such as 0, l.5 cm, and 3 cm into the scat tering volume). If the magnitudes of the elements can be rounded off to the near est 0.01, a particle size dependence is described by the resulting average mat rices, which is only two matrices for d >0.22 μm and d <0.22 μm which are nonsingular and asymmetric, respectively.     

Phase Equilibria of the Sn-Ni-V System at 800°C

Ternary Sn-Ni-V alloys were prepared and annealed at 800°C for 60 days. The annealed alloys were metallographically examined, and the equilibrium phases formed were identified on the basis of compositional determinations and x-ray diffraction analysis. The isothermal section of the ternary Sn-Ni-V system at 800°C was proposed. Two ternary compounds, VNi₂Sn and V₂NiSn, were found in the system. V₂NiSn is nearly a stoichiometry compound, while VNi₂Sn has a wide composition range at 800°C. It spans 24.6 at.% to 49.6 at.% V, 50.6 at.% to 31.2 at.% Ni, and 19.2 at.% to 24.8 at.% Sn. VNi₂Sn (30V-45Ni-25Sn) has a congruent melting temperature of 1095.6°C. Moreover, the maximum solubility of V in Ni₃Sn₂ can reach 10.3 at.%, and that in Ni₃Sn is 1.9 at.%. Up to 4.2 at.% Ni dissolves in V₃Sn.     

90° SOI optical hybrid for Radio-over-fibre links

Radio-over- fibre (RoF) technology is receiving large attention due to its ability to provide simple antenna front ends, increased capacity and increased wireless access coverage. Coherently detected RoF systems would enable the information to be carried in both the amplitude and phase or in different states of the polarisation of the optical field. Additionally, the selectivity of coherent receiver is very well suited for access networks. We present a 90° optical hybrid built on a silicon-on-insulator planar light-wave circuit, which can be used as the optical front end of the digital coherent receiver in a digitised RoF link and will lead to reduced receiver footprint and cost. The optical hybrid circuit includes 2?×?2 and 4?×?4 multimode interference (MMI) splitters, in a polarisation diversity configuration. The simulation results at vacuum wavelength 1,550 nm show polarisation independence and phase errors between the ports of less than 0.03°. The properties of the prototyped 4?×?4 MMI were measured over a wide range of wavelengths. The 2?×?2 and 4?×?4 MMI showed nearly equal splitting ratios. Measurements of the relative phase relationship between the ports for Transverse Electric mode polarisation are shown to match the simulation results.     

The Isothermal Section of the Sn-Sb-Ni Ternary System at 270°C

Phase equilibria of the Sn-Sb-Ni ternary system at 270°C are experimentally determined in this work. Experimental results reveal both the Sn₃Sb₂ and β-SnSb phases, and thus the phase relationship near the Sn-rich corner differs from that in the 250°C isothermal section. Instead of a liquid + Ni₃Sn₄ + β-SnSb three-phase region, liquid + Ni₃Sn₄ + Sn₃Sb₂, Ni₃Sn₄ + Sn₃Sb₂ + τ, and Sn₃Sb₂ + β-SnSb + τ three-phase regions are found near the Sn-rich corner. A ternary phase (τ) is found, with stoichiometry of Ni(Sn_1?x ,Sb _x )₃, x = 0.5 to 0.78. Additionally, the Ni₃Sn₂ and NiSb phases form a continuous solution. The Ni₃Sn and Ni₃Sb phases have different structures, and thus they do not form a continuous phase region. The Ni₃Sb phase has an extended Sn solubility of 14.9 at.%, while the maximum Sb solubility in the Ni₃Sn phase is 3.2 at.%.     

Linear Polarization Components of Scattered 90°

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Group Theory Approach for the Stimulated Raman Scattering in Fiber

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Optimization of the UTC-PD Epitaxy for Photomixing at 340 GHz

We present a method to optimize the epitaxial layer structure of an InGaAs/InP uni-traveling-carrier photo-diode (UTC-PD) for continuous THz-wave generation. The design approach used is general in that it can be applied for any target frequency while this study focuses on 340 GHz. The photodiode epitaxy is modeled and optimized using a TCAD software implementing the hydrodynamic semiconductor equations. This physical device model was found to be in good agreement with reported experimental results. It is shown that the UTC-PD can generate ~1 mW at 340 GHz by choosing the optimum absorption layer and collection layer thicknesses.     

Experimental Determination and Thermodynamic Modelingof the Sn-Rich Corner of the Ternary Ni-Pd-Sn PhaseDiagram at 250°C

The Sn-rich portion of the phase diagram for the Ni-Pd-Sn ternary system was preliminarily obtained by interpolation of the three constituent binary systems using the Muggianu method. Based on this proposition, 23 Ni-Pd-Sn alloys were prepared and annealed at 250°C. The annealed alloys were analyzed by scanning electron microscopy, electron probe microanalysis, electron backscatter diffraction, and x-ray diffraction. All the binaries adjacent to the Sn-rich corner (i.e., PdSn₄, PdSn₃, PdSn₂, and Ni₃Sn₄) were found to have remarkable ternary solubility. The experimental results presented herein, together with a thermodynamic interpolation of the ternary system based on the results from the binary systems, were used to calculate the ternary phase diagram using the calculation of phase diagrams (CALPHAD) method. A substitution model was used to describe the Gibbs free energies of the liquid and solid solution phases, and a sublattice model was used to describe intermetallic compounds. A consistent set of thermodynamic parameters was obtained, ultimately leading to a better fit between the calculated results and the experimental data for this system.     

Phase Equilibria in the Ni-Sn-Zn System at 500°C

The isothermal section of the Ni-Sn-Zn ternary system at 500°C was investigated by means of x-ray diffraction (XRD), and scanning electron microscopy with energy-dispersive spectrometry (SEM/EDS). A new ternary compound with a composition of Ni₃₆Sn₄₂Zn₂₂ (in at.%) was discovered in the present study. The space group of this compound is P [`(4)] \overline{\textit{4}} 3m with lattice parameter a = 0.88283(4) nm. Two ternary phases, i.e., τ₁ and τ₂, which are derived from α′-Ni₃Sn₂ and β-NiZn, respectively, were observed to be present at 500°C. The solubility of Sn in Ni₂Zn₁₁ was determined to be about 3.5 at.%, and that of Zn in Ni₃Sn to be about 5 at.%.     

Reflectivity dependence of the lasing photon energy in GaAs junction lasers at 77°K

The reflectivity dependence, of the lasing photon energy in GaAs junction lasers at 77° K is studied. It is found that the lasing photon energy decreases with increasing values of the laser reflectivity.     

Study of the Effects of Zn Content on the Interfacial Reactions Between Sn-Zn Solders and Ni Substrates at 250°C

The interfacial reactions of Ni with Sn-Zn alloys with 1 wt.% to 9 wt.% Zn at 250°C were examined. The Zn content greatly affected the intermetallic compounds formed and microstructural evolution. A continuous Ni₅Zn₂₁ layer was formed for the Sn-Zn/Ni couples with a Zn content higher than 5 wt.%. A stable reaction layer existed at the interface and grew thicker with time. When decreasing to 3 wt.% Zn, two thin reaction layers of Ni₅Zn₂₁ and (Ni,Zn)₃Sn₄ were simultaneously observed initially, and then an extremely large faceted Ni₅Zn₂₁ phase was formed near the boundary between the Ni₅Zn₂₁ layer and the solder. Furthermore, when the Zn content was lower than 2 wt.%, the dominant phase changed to (Ni,Zn)₃Sn₄. The Zn concentration of the solder gradually decreased with reaction, and thus the interfacial stability was reduced. Subsequently, a large amount of (Ni,Zn)₃Sn₄ grains were dispersed into the molten solder, and finally the reaction product at the interface changed to Ni₃Sn₄.     

Photodetectors with 384 × 288 Matrix Elements for the Infrared Range of 8–10 Microns

Journal of Communications Technology and Electronics - Abstract—Design and fabrication of photosensitive array elements in the 384 × 288 element format with a step of 25 μm with a...     

Solutions of the Equations for Space-charge Electron Flow with a Magnetic Field at the Cathode for Beams of Non-uniform Current Density†

After a discussion of the space-charge equations, a solution is given from which the critical conditions are obtained for flows like Brillouin flow but with a magnetic field at the cathode. Results for confined flows are derived; it is shown that, compared with a beam of uniform current density, much more current can be put into a beam of given boundary voltage if the current density increases strongly with radius. Confined ribbon beams are also considered.     

The Influence of the Crystal Structure of the GaSb–InAs Matrix on the Formation of InSb Quantum Dots

Semiconductors - Uniform arrays of the InSb quantum dots with a surface density of nQD = 2 × 109 cm–2 were obtained by liquid phase epitaxy on a matrix layer based on a multicomponent...     

Performance Study of 90° Bend Substrate Integrated Waveguide Band-Pass Filter with Multi-transmission Zeroes for MIC Applications

Wireless Personal Communications - In wireless sensor networks, the privacy of an event is critical to its safety. The location privacy of the sensor node that reports the event is imperative to...     

Effects of Minor Amounts of Zn on the Sn-Zn/Ni Interfacial Reactions and Phase Equilibria of the Ternary Sn-Zn-Ni System at 250°C

This study investigated the effects of minor Zn additions (less than 1 wt.%) to pure Sn on the phase formation and microstructural evolution at the interfaces between Ni and Sn-Zn solders. When the Zn content was less than 0.3 wt.%, the reaction product was Ni₃Sn₄, which had no Zn solubility. By contrast, for reactions with more than 0.4 wt.% Zn, one high-Zn-containing phase (about Sn-35 at.%Ni-20 at.%Zn) was formed, which was proven to be a ternary intermetallic compound, the τ-phase. In addition to composition analysis, x-ray diffraction (XRD) analysis revealed that the crystallographic structure of the τ-phase was different from that of Ni₃Sn₄. Furthermore, a partial isothermal section in the Sn-Zn-Ni ternary system (less than 40 at.% Ni) at 250°C was experimentally determined to contain 12 different Sn-Zn-Ni alloys. Three three-phase regions were identified: Ni₃Sn₄ + τ + liquid, Ni₅Zn₂₁ + τ + liquid, and Ni₅Zn₂₁ + Zn + liquid. The equilibrium phase boundaries for liquid separately with Ni₅Zn₂₁, τ, and Ni₃Sn₄ were highly consistent with the Zn concentrations where the phase transitions occurred in the interfacial reactions.     

Self-Consistent Drift–Diffusion Transport in Thermoelectricsand Implications for Measuring the Scattering Parameter

We present a microscopic model of the Seebeck effect based on a generalized drift–diffusion equation and use it to predict a simple relationship between the electric field within an operating thermoelectric and the scattering parameter. Our model replicates existing theoretical results and permits an intuitive spatial picture of the Seebeck effect. A similar formalism was independently developed by Cai and Mahan, but this work includes numerical results for high dopant concentrations where the thermoelectric power factor is maximized. Based on these results, we propose that measurement of the bulk electric field should constitute a measurement of the scattering parameter, the improvement of which could lead to greater thermoelectric efficiency.     

Intermetallic growth of wire-bond at 175°C high temperature aging

Two types of samples were applied in this wire-bond evaluation work for an Al-pad diffusion process. One was finished product for the cross-section examination of wire-bond and the other was without compound encapsulant used for the plane view examination of wire-bond interface. These samples were aged at 175 C in air from 0 h to 1008 h. It is found that the normal product which was ready on board existed ∼1 μm Au₂Al and Au₅Al₂ phases. The Au₂Al phase was then transformed to Au₅Al₂ phase in a 4 ∼ 72 h aging period. The Au₄Al phase formed along with the Au₅Al₂ phase in 72 h to 240 h aging period showing some porosity within the reacted phases. The total phase thickness increased to ∼4μm after 240 h aging. The Au₄Al phase became the major phase after 336 aging h. The reacted phase layer thickness increased to ∼6 μm and reached the steady state. A titanium-rich thin layer was also induced within the reacted phase layer. Three ternary phases as AlAu₂Ti, AlAuTi, and Al₂Au₂Ti are found in this titanium-rich layer. In particular, Al₂Au₂Ti could be a new phase.