Ultrasmall demultiplexer by use of one-dimensional photonic crystal

Silica-based one-dimensional photonic crystal (1D-PC) is fabricated by use of a high-spatial-frequency grating with input and output surfaces tilted with respect to its periodic direction. An incident beam is coupled with the first photonic band in the second Brillouin zone of the 1D-PC. The output beam angle changes 3 degrees with a wavelength change of 1%. A prototype of an ultrasmall demultiplexer is demonstrated by use of a silica slab waveguide with 1D-PC.     

7-Oxo-2-thia-1-azabicyclo[3.2.0]hept-3-ene,a revised structure for penems synthesized via oxidative addition mediated by copper(I)

The structure for the fused β-lactam obtained by treatment of the secolactam $\text{3}$ with base in the presence of Cu(I)-ion is not the penem $\text{1}$(R=CH₃), but the isopenem $\text{4}$ on the basis of X-ray analysis.     

Spontaneous compactification in generalized Candelas-Weinberg models

In their recent work on the dimensional reduction, Candelas and Weinberg considered a model which is compactified into a direct product space of the Minkowski space (M₄) and an N-dimensional sphere (S_N). In the present paper we investigate generalized models of their type which are compactified into M₄ × S_M × S_N and M₄ × S_M × CP₂. The compactification is caused by the quantum loop effect due to a large number of matter fields. The conditions for the vacuum stability are studied. Numerical computation of the loop effect is undertaken, and it is shown that some of the models of the type M₄ × S_M × S_N admit a stable solution which has finite circumferences of both of the extra spaces and positive coupling constants of the Einstein-Yang-Mills theory in four dimensions.     

Theory of the intersurfacedband plasmon

The dispersion relation of the intersurfacedband plasmon, i.e., collective excitation of the surface electrons of the clean or adsorbed surfaces, is investigated by the self-consistent field approach. The dispersion is predicted to start with the linear term in the wave number parallel to the surface, which will be helpful to distinguish the plasmon from the individual excitations. The sign of the dispersion and the depolarization shift depend on the polarization of the interband transition. The contribution of the plasmon to the electron energy loss cross section is given.     

A gauge invarlant approach to two-dimensional quantum chromodynamics

Quantum chromodynamics in 1 + 1 space-time is formulated in terms of gauge invariant phase operators; i.e., the Hamiltonian as well as other Poincaré generators are written in a gauge invariant hadronic language without reference to the gluon and quark fields. A systematic method for computing the $\text{1}\text{N}$ expansion is given. Both the meson and the baryon sectors are studied in this context. It is shown that no infrared divergences appear at any step of the calculations.     

Novel competing reaction of 1-methoxy-2-(trimethylsilyl)-3-hydroxy moiety in base-induced peterson olefination; mechanistic rationale of the reaction

In the base-induced Peterson olefination of diastereomerically pure 8-methoxy-7-(trimethylsilyl)-6-tridecanol, anti pathway to eliminate a methoxide ion was found to compete significantly with amply precedented syn-elimination of a trimethylsilanolate ion. On the basis of an extent of the competing reactions which depend markedly on the respective diastereomers (three from four diastereomers) the detailed mechanism of the syn-elimination emerged.