Showing papers on "Total external reflection published in 2013"

Ultrafast plasmonics using transparent conductive oxide hybrids in the epsilon-near-zero regime

Abstract: The dielectric response of transparent conductive oxides near the bulk plasmon frequency is characterized by a refractive index less than vacuum. In analogy with x-ray optics, it is shown that this regime results in total external reflection and air-guiding of light. In addition, the strong reduction of the wavevector in the indium-tin oxide below that of free space enables a new surface plasmon polariton mode which can be excited without requiring a prism or grating coupler. Ultrafast control of the surface plasmon polariton mode is achieved with a modulation amplitude reaching 20%.

Infrared shielding film

Abstract: An infrared shielding film includes a laminated body including a high refractive index layer and a low refractive index layer, the high refractive index layer and the low refractive index layer being alternately laminated and including a high refractive index material and a low refractive index material, respectively, and the high refractive index material and the low refractive index material having mutually different refractive indexes The infrared film also includes a primary reflection unit providing a primary reflection band with reflectivity exceeding 60% in near-infrared region in reflection spectra of the infrared shielding film for incident light angles of 0° and 60° In a short-wavelength side of the primary reflection band, wavelengths exhibiting 70% reflectivity of the peak value in the primary reflection band are referred to as s(0) nm and s(60) nm, respectively, a relationship s(60) nm>700 nm is satisfied

X-ray spectroscopy of fluorescence radiation channeling in μ-capillary holed glass plates

Abstract: Capillary optics is a fundamental X-ray technology capable of generating a high flux density with sub μm spot size. The physical basis of capillary optics refers to the mechanism of the total external reflection of X-rays although experimental data about the transport of the radiation inside such kind of structures are really limited. We present here the data of reflection and transmission soft X-ray synchrotron radiation experiments performed with different types of microchannel plates. In particular, we discuss the presence of fine structures in the XANES spectra at the energy of the Si L-edges detected at the exit of micro-capillary structures under the condition of the total X-ray reflection.

Total internal reflection at a boundary between vacuum and an optical medium with quasi-zero refractive index

Abstract: It is shown that, on a surface of optical transparency of a medium with quasi-zero refractive index, surface optical waves traveling along the surface can be excited for different angles of incidence of external radiation. Expressions for the amplitudes of nonspecular reflection and transmission of light waves at an inhomogeneous boundary between two media are derived. Using these expressions, the boundary reflectance and transmittance for different angles of incidence and refraction can be calculated.

Two methods for general laws of reflection and refraction for metasurface with phase discontinuity

Abstract: Considering the abrupt phase shift at the interface between the two media,the general reflection and refraction laws at the metasurface with the abrupt phase shift are derived by the two methods based on Fermat's principle and the boundary conditions of continuity,respectively.It is found that the tradition reflection and refraction laws are the special cases of the generalized reflection and refraction laws when the phase shift gradient is equal to zero.Based on the generalized laws of reflection and refraction,the occurrence conditions of the total internal reflection and the full transmission are given and the effect of the refraction index and the phase shift gradient are discussed.It is shown that the arbitrary controlling of the electromagnetic waves can be easily achieved.

X-ray phase imaging with a laboratory source using selective reflection from a mirror

Abstract: A novel approach for hard x-ray phase contrast imaging with a laboratory source is reported. The technique is based on total external reflection from the edge of a mirror, aligned to intercept only half of the incident beam. The mirror edge thus produces two beams. The refraction x-rays undergo when interacting with a sample placed before the mirror, causes relative intensity variations between direct and reflected beams. Quantitative phase contrast and pure absorption imaging are demonstrated using this method.

General laws of reflection and refraction for subwavelength phase grating

Abstract: The general reflection and refraction laws at the metasurface with the abrupt phase shift were derived by two different methods of Fermat's principle and the boundary conditions respectively. It is found that one or two critical angles for total internal reflection exist when a light hits on the optical sparse material from the optical denser material, and one such a critical angle exists when light spreads from the optical sparse material to the optical denser material. Anomalous reflection and refraction, such as, negative reflection and negative refraction may occur when a light passes through the metasurface, and the conditions of their occurrence were given. Finally, a kind of metasurface based on one-dimensional phase mask was designed to control the light propagation.

Properties of prismatic structures consisting dielectric waveguide

Abstract: Structure consisting glass prism on which step-by-step dielectric layer with low refractive index and dielectric layer with high complex refractive index were deposited was analyzed by matrix method. It was indicated that reflection is zero for certain wavelengths and responsible angles of incidence in cause of use absorption layer. And reflection tends to infinity for certain wavelengths and responsible angles of incidence if waveguide layer has amplifying properties.

Disappearance of allowed bands in light scattering from a binary photonic crystal beyond the second critical angle

Abstract: We consider light scattering from a binary (two-layered) photonic crystal. When the index of refraction of the incident medium exceeds that of either layer, total internal reflection may occur, which is a type of phase transition. At band edges (similar to the case where the index of refraction of the incident medium is less than those of the layers), the two Bloch waves describing propagation become degenerate and a hybrid Floquet mode is required to understand the response. For angles of incidence exceeding the second critical angle (when total internal reflection occurs in both layers), the allowed bands disappear entirely.

Reflection type liquid crystal display device and electronic device

Abstract: PROBLEM TO BE SOLVED: To provide a reflection type liquid crystal display device that makes it possible to attain thinness, while improving contrast, and to provide an electronic device having the reflection type liquid crystal display device provided.SOLUTION: The reflection type liquid crystal display device has: a reflection electrode; a first substrate; a transparent electrode; a second substrate; a liquid crystal layer; and a sheet-like anisotropic scattering member laminated onto the second substrate. A low refractive index area and a high refractive index area higher in a refractive index than the low refractive index area are mixed in the anisotropic scattering member. The anisotropic scattering member is arranged at a position where light scatters when external light enters from a surface side where a degree of a change in the refractive index in the vicinity of a boundary between the low refractive index area and the high refractive index area is relatively large and emerges from a surface side where the degree of the change in the refractive index in the vicinity of the boundary between the low refractive index area and the high refractive index area is relatively small, and causes a phase difference to be generated in a fixed direction with respect to the entered external light.

A novel monochromator for ultrashort soft x-ray pulses

Abstract: Reflection zone plates (RZP), which consist of elliptical zone plates fabricated on a total external reflection mirror surface, can be effectively used to produce a monochromatic x-ray beam and to focus it at photon energies below 1400 eV. However, as RZPs are highly chromatic, they can be designed only for one specific photon energy. We alleviate this problem by using a novel approach: a Reflection Zone Plate Array (RZPA). Here, we report about successful implementation of novel monochromator based on RZPAs for experiments with 100 fs time resolution at the upgraded Femtoslicing facility at BESSY-II. Aiming at minimum losses in x-ray flux up to 2000 resolution, we fabricated and used an RZPA as a single optical element for diffraction and focusing. Nine Fresnel lenses, designed for the energies of 410 eV, 543 eV, 644 eV, 715 eV, 786 eV, 861 eV, 1221 eV and 1333 eV which correspond to the absorption edges of NK, O-K, Mn-L, Fe-L, Co-L, Ni-L, Gd-M and Dy-M, were fabricated on the same substrate with a diameter of 100 mm. At resolution E/ΔE up to 2000 all edges of other elements in that range (400-1400 eV) are covered, too.

Control of the index of refraction in optically dense medium

Abstract: In this work we investigate conditions of emergence and destruction of the electromagnetically induced transparency effect in the optically dense medium of atoms which are excited along closed contour of excitation by the three frequency radiation. We found the conditions under which index of refraction of the medium acquires spatial quasi-periodic dependence. It is possible to control this dependence by variation of the initial phases and intensities of the electromagnetic fields.

An experimental setup for studying specular reflection of hard γ quanta

Abstract: An experimental setup is described on which the fact of specular reflection of hard γ quanta (E γ ≤ 5 MeV) from a smooth amorphous surface has been experimentally established. Specular reflection is observed at sliding incidence of γ quanta onto a reflecting surface at angles of a few thousandths of a degree. The setup is composed of a microtron, a system of electron transportation to a bremsstrahlung target, the bremsstrahlung target generating an intense directed flux of electron bremsstrahlung γ quanta), a guiding system forming a ribbon beam of γ radiation with a width of ∼1 cm and a thickness of ≈20 μm, a reflector (a liquid mercury surface or a glass plate), and a detection system containing the counting and spectrometric detectors located at a distance of 120 m from the bremsstrahlung target. Some experimental results are presented.

Ultrafast plasmonics using transparent conductive oxide hybrids in the epsilon near-zero regime

Abstract: The dielectric response of transparent conductive oxides near the bulk plasmon frequency is characterized by a refractive index less than vacuum. In analogy with x-ray optics, it is shown that this regime results in total external reflection and air-guiding of light. In addition, the strong reduction of the wavevector in the ITO below that of free space enables a new surface plasmon polariton mode which can be excited without requiring a prism or grating coupler. Ultrafast control of the surface plasmon polariton mode is achieved with a modulation amplitude reaching 20%.

Principles of X-ray diffractometry of surface acoustic waves

Abstract: Theoretical fundamentals of modern methods of X-ray diffractometry of surface acoustic waves (SAW) are considered briefly. X-ray diffraction on SAW-modulated crystals under total external reflection conditions and the Bragg conditions for the YZ-cut of the LiNbO3 crystal is considered. Agreement of theoretical and experimental results makes it possible to use them for SAW diagnostics. Possibilities and limitations of listed methods for determining the SAW field parameters are discussed.

Total internal reflection of light scattered from a rugate

Abstract: We consider scattering of light from a rugate thin film in the case of total internal reflection. This might occur if the refractive index of the incident medium exceeds that encountered in the rugate.