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Showing papers on "Total external reflection published in 2009"


Journal ArticleDOI
TL;DR: In this article, the feasibility of negative refraction with reduced absorption in coherently driven atomic media was discussed and a generalized expression for the impedance of a medium with magnetoelectric cross coupling was derived.
Abstract: We discuss the feasibility of negative refraction with reduced absorption in coherently driven atomic media. Coherent coupling of an electric and a magnetic dipole transition by laser fields induces magnetoelectric cross coupling and negative refraction at dipole densities which are considerably smaller than necessary to achieve a negative permeability. At the same time the absorption gets minimized due to destructive quantum interference and the ratio of negative refraction index to absorption becomes orders of magnitude larger than in systems without coherent cross coupling. The proposed scheme allows for a fine tuning of the refractive index. We derive a generalized expression for the impedance of a medium with magnetoelectric cross coupling and show that impedance matching to vacuum can easily be achieved. Finally we discuss the tensorial properties of the medium response and derive expressions for the dependence of the refractive index on the propagation direction.

32 citations


Journal ArticleDOI
TL;DR: In this paper, the authors further developed recurrence formulae for the effective refractive indices associated with higher-order reflection-refraction events when the ray-transmission is from a particle to air.
Abstract: The ray-tracing technique can be employed to simulate the scattering of light by a dielectric particle whose characteristic dimension is much larger than the incident wavelength. When a scattering particle is absorptive, a localized electromagnetic wave refracted into the scatterer is inhomogeneous, which requires the use of an effective refractive index to determine the propagation direction of the refracted ray. The effective refractive index for the first-order reflection–refraction event (i.e., the case for the ray-transmission from air into a particle) has been previously derived by the authors. In this study, we further develop recurrence formulae for the effective refractive indices associated with higher-order reflection–refraction events when the ray-transmission is from a particle to air. It is shown from the new formulae that effective refractive indices in this case depend upon ray history. Numerical results indicate that the real and imaginary parts of the effective refractive index are larger and smaller, respectively, than the real and imaginary parts of the inherent complex refractive index of an absorbing particle. Furthermore, if the particle faces associated with two sequential internal reflections are parallel to each other, the corresponding effective refractive indices are the same.

23 citations


Patent
18 May 2009
TL;DR: In this paper, a non-quarter wave multilayer structure with a plurality of alternating low index of refraction material stacks and high index of material stacks was proposed. But the structure was not shown to be stable in the presence of a narrow band of electromagnetic radiation.
Abstract: The present invention discloses a non-quarter wave multilayer structure having a plurality of alternating low index of refraction material stacks and high index of refraction material stacks. The plurality of alternating stacks can reflect electromagnetic radiation in the ultraviolet region and a narrow band of electromagnetic radiation in the visible region. The non-quarter wave multilayer structure, i.e. n L d L ≠n H d H ≠λ 0 /4, can be expressed as [A 0.5 qH pL(qH pL) N 0.5 qH G], where q and p are multipliers to the quarter-wave thicknesses of high and low refractive index material, respectively, H is the quarter-wave thickness of the high refracting index material; L is the quarter-wave thickness of the low refracting index material; N represents the total number of layers between bounding half layers of high index of refraction material (0.5 qH); G represents a substrate and A represents air.

21 citations


Journal ArticleDOI
TL;DR: In this paper, the view that a light beam makes a detour through the thinner medium must be modified, where a fraction of the incident light is diverted into the associated inhomogeneous wave, which rejoins on the other side at the outgoing beam.
Abstract: The view that, during total reflection, a light beam makes a detour through the thinner medium must be modified. At one side of the reflection, a fraction of the incident light is diverted into the associated inhomogeneous wave in the thinner medium, which rejoins on the other side at the outgoing beam. In the field undergoing total reflection, in which the incident and reflected wave beams are characterized by their intensity minima, circulating waves appear. These latter waves are areas where the time-averaged energy flow circulates in closed streamlines.

16 citations


Journal ArticleDOI
TL;DR: In this paper, the regimes for transforming a real frequency into a complex one were discovered for the reflection and transmission of monochromatic radiation incident on a moving inhomogeneity of medium characteristics.
Abstract: For the problem of the reflection and transmission of monochromatic radiation incident on a moving inhomogeneity of medium characteristics, the regimes for transforming a real frequency into a complex one are discovered. This makes it possible to develop spectroscopy of complex frequencies for absorbing media or near the regime of total internal reflection. It is also shown that, taking into account the complex frequencies, Doppler frequency shifts are found unambiguously if initial conditions for radiation and medium are specified.

10 citations


Journal ArticleDOI
TL;DR: In this paper, the reflection coefficient of a thin-film metal-dielectric structure at light incidence angles greater than the critical angle of total internal reflection was obtained using a conducting surface model for a thin absorbing layer.
Abstract: Analytical formulas for calculating the reflection coefficient of a thin-film metal-dielectric structure at light incidence angles greater than the critical angle of total internal reflection were obtained using a conducting surface model for a thin absorbing layer. It is shown that an asymmetric interference pattern of the spectral dependence of the reflection coefficient has higher sensitivity to changes in the refractive index of the medium.

9 citations


Patent
21 Sep 2009
TL;DR: In this article, a solar cell having a reflective structure is characterized in that the N layer is a layer of low refraction index, and a refractive index of the layer is lower than that of the I layer.
Abstract: A solar cell having a reflective structure is provided, which includes a front contact, a P layer, an I layer, an N layer, and a back contact that are stacked together. The solar cell having the reflective structure is characterized in that the N layer is a layer of low refraction index, and a refraction index of the layer of low refraction index is lower than that of the I layer. Furthermore, the N layer may be a multi-layer structure consisting of several films in which films with low refraction indexes and films with high refraction indexes are stacked alternately. The film in contact with the I layer in the multi-layer structure is a film of low refraction index. A refraction index of the film of low refraction index is lower than that of the I layer.

8 citations


Journal ArticleDOI
TL;DR: In this article, a series of reflection resonances formed by the hyperfine components of the D2-lines in the spectrum of the natural mixture of rubidium isotopes is studied.
Abstract: A series of reflection resonances formed by the hyperfine components of the D2-lines in the spectrum of the natural mixture of rubidium isotopes is studied. Passages from resonantly frustrated total internal reflection to resonance Brewster reflection caused by the frequency tuning of the incident light are demonstrated experimentally. The contrast of the strongest refection resonances exceeds 500% at the moderate heating of reflecting cells. The intensity of the reflected light changes in this case by more than 20 times. A theory is developed which is based on a two-level model for resonance atoms and Fresnel formulas for reflection coefficients. Numerical calculations based on the proposed theory confirm main experimental results.

7 citations


Journal ArticleDOI
TL;DR: In this paper, a nondestructive method for monitoring the stationary process of the formation of micrometer-sized porous silicon layers and estimating their porosity and thickness is proposed.
Abstract: An X-ray analysis of porous silicon layers (Sb-doped n +-Si(111)) obtained by anodic oxidation for different times with a current of 50 mA/cm2 is performed by the methods of double-crystal rocking curves and total external reflection. A nondestructive method for monitoring the stationary process of the formation of micrometer-sized porous silicon layers and estimating their porosity and thickness is proposed. The parameters obtained for porous silicon layers with a thickness of ∼6 μm are confirmed by the joint processing of diffraction curves for the 111 and 333 reflections on the basis of the developed model of dynamic scattering from layers while taking into account the strain profiles Δd(z)/d, the static Debye-Waller factor f(z), and the porosity P(z). The advantages and drawbacks of the proposed method are discussed.

6 citations


Journal ArticleDOI
TL;DR: In this article, the slow light effect in a dielectric slab waveguide with a negative refractive index photonic crystal substrate is numerically investigated, and the result demonstrates that light speed can approach zero at two adjacent frequencies, which is also verified by finite-difference time domain (FDTD) simulation.

5 citations


Journal ArticleDOI
TL;DR: The reflected and incident polarization states are nearly identical in the presence of such small phase errors.
Abstract: Monochromatic light, which is polarized in an arbitrary state, is totally internally reflected at angle of incidence ϕ=45° without change of polarization by a right-angle prism of refractive index n0=1+1/2=1.70711 (e.g., N-LAK8 Schott glass at wavelength λ=706 nm), which is coated with a transparent thin film of refractive index n1=(1+1/2)1/2=1.30656 (e.g., vacuum-deposited fluoride material) and of metric thickness equal to half of the vacuum wavelength of incident light, d=λ/2. The ambient medium of evanescent refraction is assumed to be vacuum, air, or an inert gas. Wavelength shifts of +/-50 nm, or changes of the internal angle of incidence of +/-1° around 45°, cause phase errors of only a few degrees. The reflected and incident polarization states are nearly identical in the presence of such small phase errors.

Journal ArticleDOI
TL;DR: In this article, an exactly solvable problem concerning the transition from photons in vacuum to particles in dielectric media is proposed, where the rest mass, the momentum, and the total energy of material particles are the functions of the refractive index of the medium and the wavelength of the incident light.
Abstract: Wave-particle duality is a foundation for modern science. The speed of light waves in dielectric media is less than c. The corresponding particles thus have mass. Combining wave-particle duality with the theory of relativity, an exactly solvable problem was proposed, concerning the transition from photons in vacuum to particles in dielectric media. The rest mass, the momentum, and the total energy of material particles are shown to be the functions of the refractive index of the medium and the wavelength of the incident light. The proposed relationships were applied to study the wavelength-dependent index of refraction of dielectrics and the correlation of the refractive indices of anisotropic crystals, which were confirmed by the experimental results. Variation of the refractive index with wavelength is found to obey the proposed relation. The refractive indices of anisotropic crystals are shown to be the correlated quantities.

Patent
03 Mar 2009
TL;DR: In this paper, a total reflection attenuation probe made of an optical material with a refraction index selected to make the dive depth not less than 150nm is used, the measurement subject is kept in contact with the interface with the total-reflection probe, and the far-ultraviolet light is made incident on the interface at an incident angle not more than the critical angle and in the range of the measurement wavelength so that the depth becomes not less then 150nm, total reflection light from the interface is measured to obtain absorption of light of a measurement subject.
Abstract: A total reflection attenuation type far-ultraviolet spectroscopy measures total reflection light by setting a depth to which an evanescent wave of the total reflection light dives not less than 150nm in a range of a measurement wavelength of a far-ultraviolet light region, wherein the dive depth is determined by a wavelength of the far-ultraviolet light, a refraction index of the measurement subject, a refraction index of an optical material of a total reflection attenuation probe, and an angle of the ultraviolet light incident on an interface between the probe and the measurement subject. Here, the total reflection attenuation probe made of an optical material with a refraction index selected to make the dive depth not less than 150nm is used, the measurement subject is kept in contact with the interface with the total reflection attenuation probe, the far-ultraviolet light is made incident on the interface at an incident angle not less than the critical angle and in the range of the measurement wavelength so that the dive depth becomes not less than 150nm, total reflection light from the interface is measured to obtain absorption of light of the measurement subject.

Journal ArticleDOI
TL;DR: In this article, the reflected and refracted electromagnetic fields for an ideal semi-infinite (half-space) plasma, as well as the reflection coefficient, were computed by using a general procedure based on equations of motion and electromagnetic potentials.

Journal ArticleDOI
TL;DR: In this paper, the model of a conducting surface for calculating the reflection coefficient and phase shift of light reflected from a thin metal film at the interface between two dielectrics under the conditions of frustrated total internal reflection is analyzed.
Abstract: Formulas of the model of a conducting surface for calculating the reflection coefficient and phase shift of light reflected from a thin metal film at the interface between two dielectrics under the conditions of frustrated total internal reflection are analyzed. The effect of additional dielectric layers is discussed.

Book ChapterDOI
01 Jan 2009
TL;DR: In this paper, the authors describe methods for measuring the nonlinear refraction of nominally transparent materials that involve propagation from the near to the far field, which changes a phase distortion into an amplitude redistribution.
Abstract: We describe methods for measuring the nonlinear refraction of nominally transparent materials that involve propagation from the near to the far field, which changes a phase distortion into an amplitude redistribution. These methods include beam distortion methods and Z-scan. We also look at methods to determine the spectral dependence of these changes in refractive index. Recent advances here include using femtosecond white-light continua as the source for Z-scan. The types of nonlinear refractive mechanisms are also briefly discussed including bound-electronic, excited state or free-carrier generation, reorientation, electrostrictive, and thermal nonlinear refraction as well as cascaded second-order nonlinearities.

Proceedings ArticleDOI
23 Oct 2009
TL;DR: In this paper, the porosity values of PbTe and PbSe epitaxial films on silicon substrates subjected to anodic electrochemical etching in a Norr electrolyte was carried out.
Abstract: In this work application of x-ray total external reflection method for the determination of the porosity value of PbTe and PbSe epitaxial films on silicon substrates subjected to anodic electrochemical etching in a Norr electrolyte was carried out. It is shown that the porosity values of the films can be in the range of 10-68% depending on the anodizing conditions. Triple-crystal x-ray diffractometry method was utilized for the estimation of quantitative characteristics of the pore dimensions along different directions. Nanometer-range pore dimensions and shape are estimated.

Proceedings ArticleDOI
23 Sep 2009
TL;DR: In this article, a new x-ay metrology was developed for profiling surface periodic structure of discrete track patterned media. But the measured x-ray scattering pattern is reflected to the average cross-sectional profile of the grating.
Abstract: We have developed a new x-ay metrology for profiling surface periodic structure of discrete track patterned media. X-rays irradiate surface of the discrete track media with a shallow glancing angle, which is close to the critical angle of total external reflection of the surface material. The measured x-ray scattering pattern is reflected to the average cross-sectional profile of the grating. Resist pattern of circular discrete track with120 nm-pitch on 65 mmφ magnetic disc is analyzed by the present x-ray metrology. The obtained profile, for example, line width, height of the track and so on are well agreed with that observed by cross-sectional scanning electron microscopy. The wavelength of x-ray that we use is 0.154093 nm and it is enough shorter than the critical length of the grating structure, even when the track width becomes 10 nm or less. Therefore, the resolution of the x-ray metrology will be maintained well that of required in future. In addition, x-ray metrology is able to profiling the cross-sectional structure with nondestructively due to hightransmissivity of x-rays for the materials. Furthermore, the optical parameter of the materials is well established in x-ray region, therefore, it is applicable not only resist patterns, but also real device patterns only with certain physical/optical parameters.

Journal ArticleDOI
TL;DR: In this article, the reflection condition and the angle formed by the boundary line between incident and reflected waves and boundary line separating two regions of different kinetics are theoretically given, and the theoretical results are supported by numerical results.
Abstract: The reflection of plane waves in oscillatory media described by complex Ginzburg-Landau equation has been researched. The reflection condition and the angle formed by the boundary line between incident and reflected waves and the boundary line separating two regions of different kinetics are theoretically given. Two kinds of reflections have been found. One is a back refraction-induced reflection. The corresponding angle is theoretically obtained. The other is a pure reflection, which is independent of refraction. The theoretical results are supported by numerical results. The theoretical and numerical results show that the reflection takes place only if the angle of incidence is larger than a critical value. The angle of reflection is equal to the critical angle of incidence, and it increases as the frequency of the incident wave increases for the pure reflection.

Journal ArticleDOI
TL;DR: The problem of reflection and refraction of TE and TM-polarized electromagnetic waves at oblique incidence on a dielectric-biisotropic medium interface has been solved in this paper.
Abstract: The problem of reflection and refraction of TE- and TM-polarized electromagnetic waves at oblique incidence on a dielectric-biisotropic medium interface has been solved. Conditions for the Brewster angles, at which the reflected wave field contains only the cross-polarized component, are established and the influence of the chirality and nonreciprocity parameters on the reflection coefficients is analyzed. It is shown that the appearance of cross-polarization upon reflection from the biisotropic medium is caused by the presence of nonreciprocity in addition to chirality.

Posted Content
TL;DR: In this paper, Fourier inversion of the XSW induced modulation in the X-ray fluorescence (XRF) yield from a specific atomic distribution within the overlayer directly produces a model-independent 1-D atomic density profile.
Abstract: Fresnel theory is used to derive the complex electric-fields above and below an X-ray reflecting interface that separates two materials with differing indices of refraction. The interference between the incident and reflected waves produces an X-ray standing wave (XSW) above the reflecting interface. The XSW intensity modulation is strongly enhanced by the total external reflection (TR) condition, which occurs at incident angles less than the critical angle. At these small milliradian incident angles the XSW period (lambda/2theta) becomes very large, which makes the TR-XSW an ideal probe for studying low-density structures that extend 1 to 1000 nm above the reflecting interface. Fourier inversion of the XSW induced modulation in the X-ray fluorescence (XRF) yield from a specific atomic distribution within the overlayer directly produces a model-independent 1-D atomic density profile. The modulation can also be used to analyze the degree of coherence in the incident X-ray beam.

Proceedings ArticleDOI
26 Sep 2009
TL;DR: In this article, a fast method for measuring the refractive-index dispersion of transparent and absorbing liquid solutions is described, which is based on measuring the reflectance spectra of an optical beam of white light in an internal reflection configuration near the critical angle defined by the incident medium (a glass prism) and that of the solvent which is assumed to be transparent.
Abstract: We describe a fast method for measuring the refractive-index dispersion of transparent and absorbing liquid solutions. The method is based on measuring the reflectance spectra of an optical beam of white light in an internal reflection configuration near the critical angle defined by the refractive indices of the incident medium (a glass prism) and that of the solvent, which is assumed to be transparent. From a few reflectance spectra taken near the critical angle with the pure solvent and the solution, the dispersion of the contribution to the refractive index of the solute (the sample) can be obtained. We present results with solutions of Rodamine 6G dissolved in distilled water and in methanol showing the feasibility of the proposed method.

Patent
03 Mar 2009
TL;DR: In this paper, the attenuated total reflection probe is made of an optical material selected so as to have the penetration depth equal to or higher than 150 nm in far ultraviolet wavelength range, and the probe makes contact with the object to be measured at the interface, and far ultraviolet light is incident on the interface at incident angle larger than critical angle in the wavelength range so that to have a penetration depth of at least 150 nm.
Abstract: In far ultraviolet spectroscopy using attenuated total reflection, total reflection light is measured by using evanescent waves of total reflection light. The penetration depth thereof is equal to or larger than 150 nm in a wavelength range in the far ultraviolet range wherein the penetration depth depends on a wavelength of the far ultraviolet light, refractive index of an object to be measured, refractive index of optical material of the probe and incident angle of the far ultraviolet light at an interface between the probe and the object. The attenuated total reflection probe is made of an optical material selected so as to have the penetration depth equal to or higher than 150 nm in far ultraviolet wavelength range, and the probe makes contact with the object to be measured at the interface, and the far ultraviolet light is incident on the interface at incident angle larger than critical angle in the wavelength range so as to have the penetration depth equal to or higher than 150 nm. The total reflection light from the interface is measured, and absorbance of the object to be measured is determined.

Proceedings ArticleDOI
20 Aug 2009
TL;DR: In this article, the authors proposed a unidirectional coupler for surface plasmon polaritons using total external reflection to enhance the coupling efficiency of the SPPs.
Abstract: The surface plasmon polaritons (SPPs) have been researched intensively, the very low coupling efficiency of the SPPs brings about difficulty in practical experiment. We proposed a unidirectional coupler for the SPPs using total external reflection. If the high-index dielectric is located on the left side of the slit, the SPPs toward the left side cannot propagate due to the cut-off property, and they should be totally reflected. By properly designing the structure parameter for constructive interference between the reflected Spp mode and the right-ward propagating SPP mode can happen, resulting in enhancement of the coupling efficiency of the SPPs.

Proceedings ArticleDOI
05 Jun 2009
TL;DR: In this article, the optical phase change between s-and p-p-polarity states is measured by analyzing the outgoing elliptically polarized beam of a linearly polarized beam.
Abstract: In undergraduate optics laboratory, one thing that is not easily achieved is quantitative measurement of optical phase. The reason is that optical phase measurement usually requires expensive interferometers. We demonstrate measurement of relative optical phase shift upon total internal reflection. Total internal reflection, though known by every student of optics, is remembered by 100% reflection at an interface when angle of incidence is greater than the critical angle, that is, it seems all the same beyond the critical angle. This is not entirely true if one considers the optical phase, which keeps changing upon total internal reflection as the angle of incidence is varied. Furthermore, for linear polarization states perpendicular to or in the plane of incidence (sand p- polarization), optical phase changes differently upon total internal reflection. Therefore, a linearly polarized beam composed of both s- and p- polarization undergoing total internal reflection becomes elliptically polarized. We show how to determine relative optical phase change between s- and p- polarization states through analysis of the outgoing elliptically polarized beam. Such optical phase change can also be theoretically calculated using Fresnel equations.

01 Nov 2009
TL;DR: In this article, a parabolic optical multimirrors using the depth-graded multilayer coatings has been proposed to create a broad band of parallel X-ray beam by the total external reflection.
Abstract: In this paper, design of parabolic optical multimirrors using the depth-graded multilayer coatings has been proposed to create a broad band of parallel X-ray beam by the total external reflection. A coupled W/Al bilayer with gradually changed thickness can be used in order to increase not only the incidence angles but also the intensity of the output parallel beam. The maximum length of mirrors can be designed lower than 4 inch due to the limitation of facilities. The thickness 5.25 ㎜ of the parallel beam was obtained using five parabolic mirrors located at the position of 1200 ㎜ far from the X-ray source at the wavelength of 0.2289㎚

Posted Content
TL;DR: In this article, the existence of both negative refraction and a negative refractive index in an optical uniaxial absorbent medium that can be characterized by ordinary and extraordinary refractive indices was demonstrated.
Abstract: This work demonstrates the existence of both negative refraction and a negative refractive index in an optical uniaxial absorbent medium that can be characterized by ordinary and extraordinary refractive indices. Negative refraction occurs in any absorbent uniaxial medium if the real part of the extraordinary index is less than its imaginary part. The refractive index is negative when the incident medium is sufficiently dense and the incident angle exceeds a critical angle that is defined here.