Laser diode integrated with a low radiation loss thickness-tapered beam expander for highly efficient fiber coupling

The optimal structure of a laser diode monolithically integrated with a thickness-tapered beam expander waveguide is demonstrated by analyzing the relationship between fiber coupling efficiencies and radiation losses. It is also found that mode conversion loss is lowered in a ridge waveguide structure than in a buried hetero structure under equivalent fiber coupling. A fabricated ridge waveguide device based on this design shows threshold current as low as 16 mA and narrow beam divergences of 13° and 12°.     

Formation and transformation of Pb2SiO4

A new modification of Pb₂SiO₄ was formed by the simultaneous hydrolysis of lead and silicon alkoxides, followed by washing and drying. It has a     

Magnetization of CeAg at high pressure

Magnetization measurements for CeAg under hydrostatic pressures up to 4.0 kbar and CeAg_1?xIn_x compounds (0.01 ? x ? 0.20) at normal pressure were made at 4.2 K in magnetic fields up to 50 kOe. It was found that the magnetization of CeAg under pressure and of CeAg_1?xIn_x were larger than that of CeAg at normal pressure.     

The primary fragmentation step of isoxazole upon electron impact. A correlation with photochemistry

Three isomeric compounds, I, II and III, were prepared and their mass spectra recorded. Comparisons of the spectra showed that the fragmentation of I proceeds only by way of II, and that II itself is transformed in part to III upon electron impact. It is suggested that selective ionization of each one of the two isolated functional groups in II may afford two isomeric radical ions, IIa and IIb. A possible interrelation to the photochemistry of these compounds is also discussed.     

The resolution of α-amino acid by chiral polymer-copper complex

The (N-benzyl-l-leucinato) copper(II) complex was shown pH titration to coordinate l-amino acids more strongly than d enantiomers. A chiral polymer complex, containing N-alkylated amino acid residue and copper(II) ion, was used partially to resolve some optically active amino acids. Unlike the (N-benzyl-l-amino acidate)-copper(II) complex, the polymer—copper(II) complex coordinates d-amino acids more strongly than l-enantiomers; the effect was explained by formation of (N,N-dialkylated-amino acidate) copper(II) complex in the polymer.     

The site distribution of Ti and V and the metal-metal interaction in the ternary system (V,Ti)5S8

The phase relations of the ternary system V_1?xTi_xS_1.57 are presented on the basis of X-ray diffractometry. The site distribution of Ti and V atoms in the structure is clarified through an NMR absorption study at room temperature. The phase relations and the site distribution of Ti and V, which appear to be closely related to each other, are discussed in terms of the metal-metal interaction of the face-shared octahedra in the metal-deficient distorted NiAs structure.     

Moiré topography from its birth to practical application

The history of the development of modern moiré topography is reviewed and the practice of making quantitative measurements of the living human body is explained. The importance of compromising between the related factors is emphasised.