Holographic vibration measurements of rough surfaces using a LCSLM

This paper describes measurements of a vibrating object with rough surface by the time-averaged method of holography using a newly designed optically addressed liquid crystal spatial light modulator with a resolution of 102 lp/mm and a diffraction efficiency of 16%. An object vibrating faster than several tens of Hz could be visualized. The pattern obtained by the method provides the locus of vibrating nodes. The advantage of this method is that a high contrast pattern of a vibrating object can be imaged in near-real-time, although the sensitivity of vibration is decreased.     

Modulated inflation

We have studied modulated inflation that generates curvature perturbation from light-field fluctuation. As discussed in previous works, even if the fluctuation of the inflaton itself does not generate the curvature perturbation, fluctuation of a light field may induce fluctuation for the end-line of inflation and this may lead to generation of cosmological perturbation “at the end of the inflation”. Our scenario is different from this kind of modulated scenario, as clearly explained in this Letter by using δN formalism. We also explain the crucial difference from the standard multi-field inflation model. We show concrete examples of the modulated inflation scenario in which large non-gaussianity can be generated. We also discuss the running of the non-gaussianity parameter.     

Multiresolution Approach to Image Reconstruction with Phase-Diversity Technique

A multiresolution analysis is adopted to improve an image reconstruction with a phase-diversity technique. The phase distribution at low resolution is first estimated and then is used as an initial estimate for phase reconstruction at a higher resolution level. Computer simulations are conducted to confirm the proposed method. The method is applied for image reconstruction of solar granulation.     

Energy transfer between excitons and plasmons in semiconductor-metal hybrid nanostructures

We summarized our recent optical studies on semiconductor nanoparticle (NP) based hybrid nanostructures: isolated CdSe NPs on Au substrates, close-packed CdSe NP monolayers on Au substrates, and close-packed monolayers of mixed CdSe/Au NPs. Luminescence properties of semiconductor-metal hybrid nanostructures were studied by space-resolved optical imaging spectroscopy and time-resolved luminescence spectroscopy. The luminescence spectra and dynamics of isolated and assembled NPs depend on the local environments. We discuss exciton-plasmon interactions in semiconductor-metal hybrid nanostructures.     

Two-dimensional and three-dimensional Fermi surfaces of superconducting BaFe2(As(1-x)P(x))2 and their nesting properties revealed by angle-resolved photoemission spectroscopy

We have studied the three-dimensional shapes of the Fermi surfaces (FSs) of BaFe(2)(As(1-x)P(x))(2) (x=0.38), where superconductivity is induced by isovalent P substitution and by angle-resolved photoemission spectroscopy. Moderately strong electron mass enhancement has been identified for both the electron and hole FSs. Among two observed hole FSs, the nearly two-dimensional one shows good nesting with the outer two-dimensional electron FS, but its orbital character is different from the outer electron FS. The three-dimensional hole FS shows poor nesting with the electron FSs. The present results suggest that the three dimensionality and the difference in the orbital character weaken FS nesting while partial nesting among the outer electron FSs of d(xy) character and/or that within the three-dimensional hole FS becomes dominant, which may lead to the nodal superconductivity.     

Fraunhofer Diffraction Pattern by a Slit Aperture between a Knife Edge and a Metal Cylinder

The Fraunhofer diffraction pattern of an aperture formed between a knife edge and a smooth surface of a turned metal cylinder or half cylinder is different from the diffraction pattern of an ideal slit aperture. The diffraction pattern is simulated by adding the light reflected by the cylinder surface to the pattern formed by a slit, and is measured using a cylinder that has been partly cut away so that it can represent either a full or half cylinder. The theoretical and measured patterns agree well with each other.