Waveguide holograms: A new approach to hologram integration

A new class of holography is proposed, in which (1) the evanescent part of a guided wave, or (2) the guided wave in a thin-film hologram is utilized as the reference wave and/or the illuminating one. The hologram was designated as “wave-guide hologram” and has advantages in the possibility of integration, wide field of view, and compactness and high reliability of the reconstructing system. The possibility of the waveguide hologram has been proved through reconstruction experiments with a guided wave of a waveguide hologram recorded with a plane reference wave.     

Phase transition in ammonium hexafluorovanadate (III)

Heat capacity of ammonium hexafluorovanadate (NH₄)₃ [VF₆] has been measured with a miniaturized adiabatic calorimeter from 20 to 300 K. A phase transition was found at 280.44 ± 0.05 K with the associated entropy change Δ_trs S = 24.9 ± 0.5 JK^?1 mol^?1. The entropy transition is accounted for by the orientational order-disorder changes of hexafluorovanadate ion and ammonium ion occupying respective octahedral sites, as in the cases of (NH₄)₃AlF₆ and (NH₄)₃FeF₆ crystals. Changes in infrared spectra relative to v₃ vibrational mode of [VF₆]^3? ion can be explained by an orientational disorder of the anions in the high-temperature phase (HTP). The dependence of cubic root of the unit-cell volume of a family of ammonium cryolites on their transition temperatures is discussed in relation to the nature of interactions which induce the phase transition.     

InGaAsP/InP optical waveguide switch operated by a carrier-induced change in the refractive index

Waveguided semiconductor optical switches operated by a carrier-induced change in the refractive-index associated with the plasma dispersion are proposed. InGaAsP/InP four-port switches having two intersecting single-mode channel waveguides are fabricated by selective liquid-phase epitaxy and investigated at 1.5m wavelength. Optical switching is observed as a result of mode interference in the waveguide intersection region.     

Simultaneous observation of CO isotopomer absorption by broadband difference-frequency generation using a direct-bonded quasi-phase-matched LiNbO3 waveguide

Rovibration absorption lines both of 12CO and 13CO are observed simultaneously with the output of a 2 microm broadband difference frequency generated in a direct-bonded quasi-phase-matched LiNbO3 waveguide, which is a 50 mm device with a single quasi-phase-matching period that is operated at a constant temperature. The wavelength conversion efficiency and the difference-frequency generation bandwidth reach 100%/W and 100 nm, respectively. The idler output bandwidth in the 2 microm region is obtained by group-velocity matching or phase-mismatch minimization when a 0.94 microm pump laser diode and a 1.55 microm tunable signal source are used.     

Tensor optimized antisymmetrized molecular dynamics for relativistic nuclear matter

We apply a newly developed many-body theory, tensor optimized antisymmetrized molecular dynamics (TOAMD), to nuclear matter using a relativistic bare nucleon-nucleon interaction in the relativistic framework. It becomes evident that the tensor interaction plays an important role in nuclear many-body system due to the role of the pion in a strongly interacting system. We take the relativistic nuclear matter (RNM) wave function as a basic state and add tensor and short-range correlation operators in the form of pion and omega-meson correlation functions acting on the RNM wave function using the concept of TOAMD. We use the Monte Carlo (Metropolis) method based on the Gaussian integration and the second quantization method for antisymmetrization to calculate all the matrix elements of the many-body Hamiltonian. We write the whole formula of the TOAMD method for numerical calculations of the nuclear binding and saturation properties of nuclear matter using one-boson exchange potential.     

Further results on graph equations for line graphs and n-th power graphs

We present solutions of seven graph equations involving the line graph, complement and n-th power operations. One such equation $\text{L(G)}{}^{\mathrm{n}}\text{=}\text{G}\text{?}$ generalizes a result of M. Aigner. In addition, some comments are made about graphs satisfying $\text{G}{}^{\mathrm{n}}\text{=}\text{G}\text{?}$.     

自然循环回路内芯片的强化沸腾换热研究

针对电子器件的高效冷却问题,对自然循环回路系统内表面加工有方柱形微结构的硅片上FC-72的强化沸腾换热性能进行了实验研究.测试了两个芯片,其表面上的方柱形微结构的边长均为30μm,但高度分别为60 μm和200 μm.沸腾介质的过冷度设为10 K、25 K和35 K.随着壁面过热度的增加,微结构表面芯片上的热流密度急剧增加且临界热流密度时芯片的表面温度低于芯片回路正常工作的临界上限温度85℃,这与其在池沸腾换热中的特点一样.但临界热流密度值与池沸腾情况相比有所降低.     

Enhancement of the Kerr effect for a quantum dot in a cavity

Nonlinear susceptibility of a quantum dot (QD) embedded in a two-sided cavity, is studied theoretically from a weak-coupling to a strong-coupling regime. In the relevance of a quantum logic gate, the corresponding nonlinear phase shifts (Kerr effect) are estimated for coherent wavepackets including one photon on average. In the weak-coupling regime, the phase shift enhances strongly as a function of a coupling constant between the cavity photon and QD, and eventually saturates in the strong-coupling regime. We also show transmission spectra to evaluate the efficiency of the phase shift. Although the efficiency decreases monotonically in the weak-coupling regime, it rises in the strong-coupling regime.     

Controlling the orientation of polar molecules with combined electrostatic and pulsed,nonresonant laser fields

We demonstrate that molecules with a moderate permanent dipole moment can be oriented with combined electrostatic and pulsed, nonresonant laser fields. We use OCS molecules as a sample. The degree of orientation can be increased by increasing the magnitude of electrostatic field and the peak intensity of the laser field or by decreasing the rotational temperature of the molecules.     

A structural study of CN treated amorphous silicon

Recently, a remarkable technique to overcome the problem of light-induced degradation in amorphous silicon (a-Si) solar cells using a cyanide (CN) treatment has been developed. Structural and bonding characteristics of CN in a-Si has been studied using ab initio molecular dynamics simulations. It was found that CN incorporation results in more than just the termination of dangling bonds. The connectivity of the covalent random network increases because the CN changes from triply bonded, which is a common form in molecular CN, to the singly bonded form. This may be the mechanism by which CN incorporation produces significant reductions in light-induced degradation.